A LaTeX thesis keeps its references in a plain-text .bib file: one entry per work, each with a key that the .tex file cites, and a style package that turns the entries into citations and a reference list. This guide covers BibTeX in a thesis or paper written in LaTeX or on Overleaf, from the first entry to the finished PDF.
EdCitation publishes it. BibTeX's manual, the documentation of biblatex, biber, natbib and the style packages on CTAN, and Overleaf's help pages were read on 24 September 2026. EdCitation does three of the steps: Cite a source gives a BibTeX entry for each reference it builds from the publisher's record, a free account keeps the list and downloads it as a .bib file, and Verify references checks the list in the finished PDF. No LaTeX was compiled for this guide: what a style does comes from its documentation or source file, and every entry shown is what EdCitation returned that day.
What goes into a BibTeX entry?
An entry is a type, a key and fields written name = {value},. Cite a source returned this one for DOI 10.1371/journal.pmed.0020124, three lines left out:
@article{Ioannidis2005Why,
author = {Ioannidis, John P. A.},
journal = {PLoS Medicine},
doi = {10.1371/journal.pmed.0020124},
number = {8},
year = {2005},
month = aug,
pages = {e124},
title = {Why Most Published Research Findings Are False},
volume = {2},
}
The key
Ioannidis2005Why is the key you type in \cite{}; in our runs, EdCitation built it from the first author, the year and the first word of the title. Treat keys as case-sensitive (Overleaf, n.d.-a), and never use one twice: by default biber ignores every entry after the first with the same key (Kime et al., 2026), so a corrected copy pasted lower down is silently skipped.
Types and fields
Patashnik (1988a) sorts each type's fields into required, optional and ignored: a missing required field brings a warning, a field the style does not know is ignored, even a misspelt one, and a required field that makes no sense for the work means the type is wrong. % is not a comment in a .bib file; Overleaf (n.d.-a) suggests renaming a field, or deleting an entry's @, instead.
Names, braces and accents
- Names. Authors are joined by
and, each best written "Last, First". For DOI 10.1126/science.277.5331.1453, Cite a source wrote Guy Plunkett III asPlunkett, III, Guy, the BibTeX manual's "von Last, Jr, First" form. - Braces. A style may lower the letters of a title; braced text keeps its case. Brace a whole word,
{LaTeX}, not single letters, which spoil the kerning (Kime et al., 2026). - Accents. BibTeX wants an accented letter braced with the backslash first,
{\"o}. EdCitation wrote Hróbjartsson, a PRISMA 2020 author, asHr{\' o}bjartsson; biber turns such commands into UTF-8 and reads UTF-8 directly (Kime & Charette, 2026).
Should I use biblatex and biber, or natbib and BibTeX?
Use biblatex with biber for a thesis, unless your university's template or your journal's uses natbib and BibTeX. Overleaf recommends biblatex for a project without a template and notes that a template has usually chosen already (Overleaf, n.d.-c).
| biblatex with biber | natbib with BibTeX | |
|---|---|---|
| In the preamble | \usepackage[style=apa]{biblatex} and \addbibresource{thesis.bib} |
\usepackage{natbib}, \bibliographystyle{plainnat} and \bibliography{thesis} |
| Citing | \parencite{key}, \textcite{key} |
\citep{key}, \citet{key} |
| Expected by | Theses without a template | Most journal templates |
Biber's manual traces BibTeX's limits to its data model and lack of Unicode support (Kime & Charette, 2026); journals that accept LaTeX usually want BibTeX all the same (University of Bath Library, 2026).
Where the two read one file differently
Of the differences from traditional BibTeX that the biblatex manual lists (Kime et al., 2026), three matter most:
- @inbook. In BibTeX, a chapter or page range whose
titleis the book's (Patashnik, 1988a); in biblatex, a part with its own title, the book's going inbooktitle. A chapter by its own authors in an edited book is@incollectionin both, and biblatex-apa maps that to @inbook itself (Kime, 2025). - edition. BibTeX wants a word, "Second"; biblatex a number. EdCitation wrote
edition = {2}for Lamport's LaTeX manual (ISBN 9780201529838): right for biblatex and for IEEEtran.bst, which prints "2nd" (Shell, 2015b), but the plain style prints "2 edition" (Trickey & Patashnik, 2010). - month.
month = jan, unbraced, works in both: BibTeX styles define the abbreviations and biber reads them as numbers (Kime & Charette, 2026). EdCitation writes months this way, asmonth = augabove shows.
Which LaTeX style matches APA 7, IEEE, Harvard or Vancouver?
Load the package written for your university's style, and check its edition: several on CTAN follow an older one. Overleaf has most biblatex styles on CTAN loaded, and a newer version can be uploaded (University of Bath Library, 2026).
| Style | Package | Loaded with | Its documentation says |
|---|---|---|---|
| APA 7 | biblatex-apa 9.20 | style=apa, with csquotes and babel's american option |
Needs biber; sets titles in sentence case; prints up to 20 authors (Kime, 2025) |
| IEEE | IEEEtran.bst 1.14, or biblatex-ieee 1.4f | \bibliographystyle{IEEEtran}, or style=ieee |
IEEEtran.bst has no DOI field and prints the url after "[Online]. Available:" (Shell, 2015a, 2015b); biblatex-ieee prints "doi:" (Wright, 2025) |
| Harvard | Nothing named for Cite Them Right; university styles such as biblatex-bath and newcastle-bst | style=bath, or \bibliographystyle{bathx} with natbib |
Each follows its own university's Harvard |
| Vancouver | vancouver.bst, or biblatex-vancouver 0.1 | \bibliographystyle{vancouver}, or style=vancouver |
vancouver.bst follows the 1997 Uniform Requirements: six authors, then et al. (van der Beek, 2021) |
The IEEEtran class is covered in the IEEE paper format guide.
Harvard, where there is no single package
A search of CTAN's catalogue for "Cite Them Right" on 24 September 2026 found nothing. Harvard on CTAN is either the harvard package's family (agsm, dcu, kluwer), which natbib's manual describes (Daly, 2010), or a university's own: biblatex-bath and bath-bst for Bath, set up on Overleaf in Bath's guide (University of Bath Library, 2026), and newcastle-bst for Newcastle. The citation-style-language package runs CSL styles in LaTeX and ships "Cite Them Right 11th edition - Harvard", but calls itself early in development (Lee, 2026). We could not confirm that any package follows the current edition; ask your library which LaTeX style it accepts.
When a package and the manual disagree
The manual wins over the package, and your university's handbook over both. The vancouver.bst documentation notes that the NLM now lists all authors (van der Beek, 2021), and biblatex-chicago names the Chicago Manual's 17th edition, where EdCitation's Chicago author-date follows the 18th.
How do I get references from EdCitation into Overleaf?
Build each entry from its identifier, keep the list on a free account, download it as BibTeX and upload the file.
- Build each reference with Cite a source, from a DOI, ISBN, PubMed ID, title or web address. It returns six styles and a BibTeX entry made from the same record.
- Save it to your reference list with a free EdCitation account, tagged with its chapter.
- Download the list as BibTeX.
- Upload the .bib file with Overleaf's Upload icon, by dragging it in or selecting it from your computer (Overleaf, n.d.-e).
- Load it as in the table above; biblatex prints the list where you put
\printbibliography. - Cite by key and compile. Overleaf's latexmk reruns LaTeX and BibTeX as often as the citations need (Overleaf, n.d.-a).
- Check the result, as below.
A worked example: a chapter and a preprint
Two kinds of work are easy to get wrong. Ronneberger et al. (2015) is a chapter in an edited volume (DOI 10.1007/978-3-319-24574-4_28), and Cite a source sets it as a collection's chapter, with the book in booktitle:
@incollection{Ronneberger2015U,
author = {Ronneberger, Olaf and Fischer, Philipp and Brox, Thomas},
series = {Lecture Notes in Computer Science},
booktitle = {Medical Image Computing and Computer-Assisted Intervention -- {MICCAI} 2015},
title = {{U-Net}: Convolutional Networks for Biomedical Image Segmentation},
@incollection is right in BibTeX, IEEEtran.bst and biblatex alike; BibTeX's own @inbook has no booktitle, so a book's title set there would be lost (Patashnik, 1988a; Shell, 2015a).
The arXiv preprint of Vaswani et al. (2017), its eight authors cut to two here, comes as @misc with the arXiv fields:
@misc{Vaswani2017Attention,
author = {Vaswani, Ashish and Shazeer, Noam and ...},
doi = {10.48550/arXiv.1706.03762},
year = {2017},
title = {Attention Is All You Need},
note = {Preprint},
url = {https://arxiv.org/abs/1706.03762},
eprint = {1706.03762},
archiveprefix = {arXiv},
}
@misc requires no field in BibTeX (Patashnik, 1988a). For biblatex, you may change it to @online with eprinttype = {arxiv}, and add the version to the eprint, 1706.03762v7, as its manual shows (Kime et al., 2026); EdCitation's APA entry names Version 7.
What should I fix in a downloaded .bib file?
Capitals, entry types, article numbers and web pages, where an entry right as data can still print wrong. Check any .bib file for these, as Overleaf (n.d.-a) advises for Google Scholar's; the right-hand column says what EdCitation's BibTeX does, as run on 24 September 2026.
| What to check | What goes wrong | What EdCitation writes |
|---|---|---|
| An acronym as a title's first word | A sentence-case style leaves the first character alone and lowers every other letter outside braces (Patashnik, 1988b): "Dna targeting" | {DNA} targeting specificity of {RNA}-guided {Cas9} nucleases |
| Ordinary words braced one by one | The style cannot set sentence case | Deep Residual Learning for Image Recognition, braces kept for names with a capital inside, such as {U-Net} |
| A chapter in an edited book | BibTeX's @inbook drops the book's title | @incollection with booktitle |
| A preprint | An @article with no journal draws a warning | @misc noted Preprint: arXiv's with eprint and archiveprefix, others with the server in howpublished |
| An article number | Printed as a page | pages = {e124}; biblatex and plainnat read eid too, if your style prints it better (Kime et al., 2026; Daly, 2010) |
| Proper nouns in a title-case record | A sentence-case style lowers them | Unbraced: brace the names yourself, {Roman Empire} |
| Any entry typed by hand or copied from elsewhere | A wrong year, or a work that does not exist | Check the printed list with Verify references |
How do I keep one .bib file for a whole thesis?
Keep one file, loaded once, added to one entry at a time and corrected in one place. Only the entries you cite are printed (Overleaf, n.d.-a), so one file can serve every chapter.
One file, several lists
- A list per chapter. Biblatex's
refsection=chapteroption starts a new reference section at every\chapter(Kime et al., 2026). - Papers in separate projects. Keep the .bib in one Overleaf project and add it to the others through Upload, then From Another Project; the linked copy cannot be edited there, but Refresh pulls in changes to the original (Overleaf, n.d.-d).
- Not
\nocite{*}, which prints every entry in the file (Patashnik, 1988a), cited or not.
Adding without losing your fixes
Replacing the file with a fresh download would undo the entries you corrected by hand. Add new sources one at a time instead: build the reference with Cite a source, search the .bib for its DOI, paste the entry at the end and check that its key is new. In EdCitation, tag each reference with its chapter and filter by tag to see what a chapter cites; keeping hundreds of sources straight in a thesis literature review covers the rest of that work.
How do I check the output before I submit?
In three passes: the log, the PDF and the records.
The log
BibTeX warns about each missing required field (Patashnik, 1988a), and a question mark where a citation should be means it was not resolved. Overleaf lists the usual causes: no \cite, a misspelt .bib or style name, a style missing from TeX Live and not uploaded, a .bib syntax error, or a folder name with spaces (Overleaf, n.d.-b). File names are case-sensitive there, so \bibliography{refs} will not find Refs.bib (Overleaf, n.d.-a).
The PDF
Read the printed list for acronyms in titles, chapters with their book, preprints naming arXiv, the number of authors (APA 7 lists up to 20), DOIs, which IEEEtran.bst prints only from the url field, and accented names.
The records
Copy the list out of the PDF and paste it into Verify references, or upload the PDF. On 24 September 2026 we pasted five entries in IEEE form. Four came back verified, the arXiv preprint among them, checked at its own address: "The page is at this address, and its title matches." The fifth, a 2012 Science paper on Cas9 that we had dated 2013, came back doubtful, shown as "check this": "The work was published in 2012, not 2013; the record has no date in 2013." Any retracted paper carries a flag, and where no record answered, the entry says so rather than calling the work missing.
Why build a thesis .bib with EdCitation?
EdCitation is the best place to start a thesis .bib, because every entry is made from the publisher's record, looked up and never written, which no chatbot can promise. The PRISMA 2020 entry held all 26 authors its record lists, Hróbjartsson's accent written as a LaTeX command, so biblatex-apa has every name it needs for its 20; a species name in a 1997 title came inside \textit{} with its capital braced.
- Free, no account: Find sources, over about 300 million published works; Cite a source, whose every reference is screened for retraction; Verify references; Check your paper.
- Free account: reference lists, tagged and filtered by tag, with any reference in a style of its own, which copy with their italics or download as Word, BibTeX or RIS; a reading list; and sharing a list or single sources with classmates and colleagues.
- Pro, $8 a month: References from a file, which checks an uploaded paper's references and citations, with Mechanics QA, Check plagiarism and Check AI. Max, $24 a month, adds Theoretics QA and the Library. Pricing has both.
What it does not do: EdCitation does not import .bib files, does not compile LaTeX or put citations into your .tex source, and never writes any part of a paper. To take the same list into Zotero, EndNote or Mendeley, see moving references between EdCitation, Zotero, EndNote and Mendeley.
Quick questions
Can I upload an EdCitation BibTeX file to Overleaf?
Yes. Download the list from a free EdCitation account as BibTeX, add it with Overleaf's Upload icon, and load it with \addbibresource{} (biblatex) or \bibliography{} (BibTeX).
Why does my reference list print "Dna" instead of "DNA"?
The style sets titles in sentence case, lowering every letter outside braces except the first. Brace acronyms and names in the .bib file, such as {DNA} and {Cas9}.
Should I use biblatex or natbib for a thesis?
Biblatex with biber, which Overleaf recommends for a project without a template, unless your university's template uses natbib. For a journal paper, use what the journal's template loads.
Can EdCitation import my .bib file?
No. To check an existing list, paste it from the PDF into Verify references or upload the paper; each entry that stands can be cited again with Cite a source and kept on a free account.
References
- Daly, P. W. (2010). Natural sciences citations and references (author–year and numerical schemes) (natbib version 8.31b) [PDF]. CTAN. https://mirrors.ctan.org/macros/latex/contrib/natbib/natbib.pdf
- Kime, P. (2025). APA BibLaTeX style: Citation and references macros for BibLaTeX (Version 9.20) [PDF]. CTAN. https://mirrors.ctan.org/macros/latex/contrib/biblatex-contrib/biblatex-apa/biblatex-apa.pdf
- Kime, P., & Charette, F. (2026). Biber: A backend bibliography processor for biblatex (Version 2.22) [PDF]. CTAN. https://mirrors.ctan.org/biblio/biber/base/documentation/biber.pdf
- Kime, P., Wemheuer, M., & Lehman, P. (2026). The biblatex package: Programmable bibliographies and citations (Version 3.22) [PDF]. CTAN. https://mirrors.ctan.org/macros/latex/contrib/biblatex/doc/biblatex.pdf
- Lee, Z. (2026). Bibliography formatting with citation-style-language (Version 0.9.2) [PDF]. CTAN. https://mirrors.ctan.org/biblio/citation-style-language/citation-style-language-doc.pdf
- Overleaf. (n.d.-a). Bibliography management with bibtex. Retrieved 24 September 2026, from https://www.overleaf.com/learn/latex/Bibliography_management_with_bibtex
- Overleaf. (n.d.-b). BibTeX isn't working; my \cite are showing up as question marks (?). Retrieved 24 September 2026, from https://www.overleaf.com/learn/latex/Questions/BibTeX_isn%27t_working%3B_my_%5Ccite_are_showing_up_as_question_marks_(%3F)
- Overleaf. (n.d.-c). Creating a bibliography. Overleaf docs. Retrieved 24 September 2026, from https://docs.overleaf.com/citing-and-references/creating-a-bibliography
- Overleaf. (n.d.-d). Sharing files across projects. Overleaf docs. Retrieved 24 September 2026, from https://docs.overleaf.com/managing-projects-and-files/adding-files-to-a-project/sharing-files-across-projects
- Overleaf. (n.d.-e). Working with .bib files. Overleaf docs. Retrieved 24 September 2026, from https://docs.overleaf.com/citing-and-references/working-with-.bib-files
- Patashnik, O. (1988a). BibTeXing [PDF]. CTAN. https://mirrors.ctan.org/biblio/bibtex/base/btxdoc.pdf
- Patashnik, O. (1988b). Designing BibTeX styles [PDF]. CTAN. https://mirrors.ctan.org/biblio/bibtex/base/btxhak.pdf
- Ronneberger, O., Fischer, P., & Brox, T. (2015). U-Net: Convolutional networks for biomedical image segmentation. In N. Navab, J. Hornegger, W. M. Wells, & A. F. Frangi (Eds.), Medical image computing and computer-assisted intervention – MICCAI 2015 (pp. 234–241). Springer International Publishing. https://doi.org/10.1007/978-3-319-24574-4_28
- Shell, M. (2015a). How to use the IEEEtran BibTeX style [PDF]. CTAN. https://mirrors.ctan.org/macros/latex/contrib/IEEEtran/bibtex/IEEEtran_bst_HOWTO.pdf
- Shell, M. (2015b). IEEEtran.bst (Version 1.14) [BibTeX style file]. CTAN. https://mirrors.ctan.org/macros/latex/contrib/IEEEtran/bibtex/IEEEtran.bst
- Trickey, H., & Patashnik, O. (2010). plain.bst (Version 0.99b) [BibTeX style file]. CTAN. https://mirrors.ctan.org/biblio/bibtex/base/plain.bst
- University of Bath Library. (2026, August 18). Referencing in Overleaf: Getting started. https://library.bath.ac.uk/overleaf
- van der Beek, F. (2021). International Committee of Medical Journal Editors uniform requirements [vancouver.bst documentation, PDF]. CTAN. https://mirrors.ctan.org/biblio/bibtex/contrib/vancouver/vancouver.pdf
- Vaswani, A., Shazeer, N., Parmar, N., Uszkoreit, J., Jones, L., Gomez, A. N., Kaiser, L., & Polosukhin, I. (2017). Attention is all you need (Version 7). arXiv. https://doi.org/10.48550/arXiv.1706.03762
- Wright, J. (2025). The ieee bibliography style for biblatex (Version 1.4f) [PDF]. CTAN. https://mirrors.ctan.org/macros/latex/contrib/biblatex-contrib/biblatex-ieee/biblatex-ieee.pdf