How to Cite in ISO 690 Style: International Bibliography Standard (2021)

This guide covers ISO 690, the international standard for bibliographic references. If you are writing for a European journal, an international conference, or an institution that requires a language-neutral reference format, ISO 690 is what is meant.

Where this page's information comes from. ISO 690:2021 is sold, not published free, so this guide does not reproduce its text or claim to. Instead:

• The standard's identity — title, edition and date — comes from ISO's own catalogue record, which we read through an Internet Archive snapshot because iso.org refuses automated requests.
• The worked element order and punctuation come from Výklad normy ČSN ISO 690: účinné od 1. 12. 2022 (Brno: Citace.com, 2023), the published interpretation of the Czech national adoption of this standard, available free as a PDF. We say so on each rule below, because a national adoption is not identical to the international text.
• Every example is a real work whose details we checked today against Crossref, DataCite, Open Library, CRAN or the publisher's own record. The identifiers are given so you can check them too.

If your department has its own ISO 690 handout, follow that instead — it will tell you which national adoption applies.

What Is ISO 690?

ISO's catalogue record gives the standard as ISO 690:2021, "Information and documentation — Guidelines for bibliographic references and citations to information resources", Edition 4, 2021-06.

The word "guidelines" in that title matters. Unlike APA or MLA, ISO 690 does not hand you one prescribed layout for each source type; it specifies which elements a reference should contain, in what order, and how an in-text citation must map to it. National adoptions and institutional guides then fix the punctuation. That is why two correctly formatted ISO 690 bibliographies can look different from one another.

In the Czech Republic the adoption is ČSN ISO 690:2022, effective 1 December 2022, which we cover in a separate guide. China's national standard, GB/T 7714, takes a different route: its 2025 edition adopts ISO 690:2021 non-equivalently, keeping the bracketed document-type codes that are peculiar to it. Brazil's own national reference standard is ABNT NBR 6023, which a Brazilian university will normally ask for instead.

Referencing Methods

The Czech interpretation lists four methods of linking a citation in the text to its reference — one more than the 2011 Czech version had — and tells you to pick one and apply it consistently:

Name–date method (Harvard)

The creator's surname and the publication year appear in the text:

Numeric method

A number in the text — in brackets, parentheses or superscript — points to the reference list, in order of first citation:

Running notes

The number corresponds to a footnote or endnote holding the reference:

Name marks

The fourth method, and the one the Czech interpretation calls new: every source gets a unique name mark — a short code such as PAZOP — which stands in the text, in round or square brackets or as a superscript, with page numbers after a comma if needed. The mark is then the first element of the reference-list entry, and the list is ordered alphabetically by mark. The interpretation's own example:

General Formatting Principles

• Unambiguous mapping: each citation must lead to exactly one reference, and each reference to one resource.
• Consistency: use the same method and the same punctuation throughout a document.
• Completeness: include enough detail to identify and locate the resource.
• Creators: the Czech interpretation's rule is that the surname is given in capitals and inverted — SURNAME, Forename — so that it stands out as the entry point.
• Multiple creators: separated by semicolons, with the last joined by "and"; up to five creators are all listed, and from six the interpretation gives the first five followed by "et al."
• Punctuation: major elements are separated by full stops, sub-elements by commas.

Citing Books (Monographs)

Element order: SURNAME, Forename. Title: subtitle. Edition. Place: Publisher, year. Extent. Series. ISBN.

Three creators, with an edition statement:

The creator element follows the same rules whatever the resource type. Four creators — all named, semicolons between, "and" before the last:

Six creators, shortened after the fifth with "et al.":

Those two show the creator element on its own; the complete references for both works — which are journal articles, not books — appear under journal articles below.

Citing Edited Books

Element order: EDITOR(S) (ed.). Title. Place: Publisher, year. ISBN.

Citing Book Chapters

Element order: AUTHOR. Chapter title. In: EDITOR (ed.). Book title. Place: Publisher, year, p. X–Y.

Note which title is italicized: the source document's, not the chapter's.

The book, its editor and its publisher are from the Open Library record; the chapter's page span is the one the University of Leeds' Harvard guide prints for this chapter, which we could not check against the book itself.

Citing Journal Articles

Element order: AUTHOR. Article title. Journal title, year, vol., no., pages. ISSN. DOI.

Print article:

Online article, with the format word and the availability statement:

Article identified by an article number rather than a page range:

Six creators, shortened:

Note the Czech interpretation's rule on numbering: each level carries the label used in the source, largest unit first — roč./vol., then č./no., then s./p. So a reference gives "2008, vol. 39, no. 4, p. 652–669", not the compressed 39(4).

Citing Websites and Online Resources

Element order: CREATOR. Page title. Online. Site name. Place: publisher, date. Available from: URL. [viewed date].

The date of citation comes after the availability statement in the 2022 Czech adoption; older guides put it before. Check which version your institution follows.

Citing Dissertations and Theses

Element order: AUTHOR. Title. Type of work. Place: Institution, year. Availability.

We have kept the author's initials rather than expanding them, because the guide we took this record from gives initials and we did not verify the full forenames. Never expand initials you have not seen spelled out. The "type of work" element is the one people get wrong; citing a dissertation explains why a repository record is the thing to copy it from.

Citing Conference Papers

Element order: AUTHOR. Paper title. In: Conference name, date, location. Place: Publisher, year, p. X–Y.

Citing Datasets

Element order: CREATOR. Dataset title [dataset]. Version. Publisher, year. Identifier.

Citing Software and Applications

Element order: CREATOR. Software name. Version. Place: Publisher, year.

R 4.3.0 was released on 21 April 2023, which we checked against the CRAN source archive — the kind of thing worth checking, because a software citation with the wrong version number points at different behaviour.

Citing Audio-Visual Materials

Element order: CREATOR. Title [medium]. Place: Publisher/Producer, year. Availability.

Film:

Podcast episode:

Citing Social Media

The 2022 Czech adoption adds rules for social media, along with artistic works, archival material and manuscripts. The element order is:

We have left this as a labelled template rather than showing a specimen post. The platforms that matter here block automated access, so we could not verify a specific live post today — and a citation example that cannot be checked is exactly what this page is trying to avoid. Copy the wording, account name, date and URL from the post in front of you.

Reference List Formatting

• Numeric method: list references in the order they were first cited.
• Name–date method: list references alphabetically by creator surname.
• Give the section a conventional heading (References, Bibliography, Works Cited) and keep one format throughout.
• Include every source cited in the text, and nothing you did not cite.

ISO 690 vs Other Styles

Because ISO 690 sets elements rather than punctuation, the source-type guides are often the faster way in: they work one real example through APA, MLA, Chicago, Harvard and IEEE side by side, so you can see which element each style keeps. Start with citing a journal article or citing a website.

Common Mistakes to Avoid

• Inconsistent formatting. Choose one method and apply it throughout.
• Compressed numbering. The Czech interpretation wants each level labelled as the source labels it — vol., no., p. (or roč., č., s.) — so 39(4) does not fit its schema.
• Lowercase surnames. Creators are given in capitals.
• Missing identifiers. Include DOIs, ISBNs, ISSNs or other persistent identifiers where the resource has them.
• The wrong element order for your version. In the 2022 Czech adoption the date of citation follows the availability statement, and the format is written as the word "Online" with no square brackets; the 2011 edition did neither.
• Assuming one correct layout. ISO 690 is guidelines. Your institution's guide decides the details.

Sources Checked

• International Organization for Standardization. ISO 690:2021, Information and documentation — Guidelines for bibliographic references and citations to information resources. Edition 4, 2021-06. Catalogue record: https://www.iso.org/standard/72642.html (read via an Internet Archive snapshot; iso.org refuses automated requests). We did not have access to the standard's text.
• FARKAŠOVÁ, Blanka; GARAMSZEGI, Tereza; JANSOVÁ, Linda; KONEČNÝ, Lukáš; KRČÁL, Martin et al. Výklad normy ČSN ISO 690: účinné od 1. 12. 2022. Brno: Citace.com, 2023. https://www.citace.com/Vyklad-CSN-ISO-690-2022.pdf — the source of the element order, creator rules and numbering rules above.
• Crossref records for 10.1057/palgrave.jibs.8400371, 10.1021/acsomega.9b00222, 10.1098/rstb.2019.0750, 10.1093/cercor/bhac378, 10.1109/EE-RDS53766.2021.9708575.
• DataCite record for 10.5281/zenodo.3939050 (creators, title, version, publisher and year).
• Open Library records for Organic chemistry (Clayden, Greeves and Warren, 2nd ed., Oxford University Press, 2012, ISBN 9780199270293) and The evolution of HIV (ed. Keith A. Crandall, Johns Hopkins University Press, 1999, ISBN 9780801861505).
• CRAN source archive for the R 4.3.0 release date (the directory listing dates R-4.3.0.tar.gz 2023-04-21), the archive.org item metadata for Nanook of the North (title "Nanook of the North (1922)", creator Robert J. Flaherty), and revisionisthistory.com for the podcast episode, whose entry reads "Season 1 • 08/18/2016". The EPA, NHS and Duke handle URLs were confirmed to resolve.