How to Cite Sources in IEEE Citation Style

IEEE citation style is the standard referencing format for electrical engineering, computer science, telecommunications, and related technical fields. Maintained by the Institute of Electrical and Electronics Engineers, the style uses a numbered reference system where each source is assigned a number in square brackets - [1], [2], [3] - in the order it first appears in the text. The full details for each reference are collected in a numbered list at the end of the paper, arranged in citation order rather than alphabetically. This guide covers the essential rules, provides worked examples for every major source type, and flags the mistakes that trip up even experienced researchers.

To generate IEEE-formatted references automatically, try the AllCitations IEEE generator. For a comparison of all available citation styles, visit the styles page.

How the IEEE Numbered System Works

Unlike author-date systems such as APA or Harvard, IEEE assigns each source a unique number the first time it is cited. That number stays with the source for the entire paper. If you cite the same source again later, you reuse the same number rather than assigning a new one.

Key rules for in-text numbered citations:

• Format: Place the reference number in square brackets on the line of text: [1]
• Order of appearance: Number sources sequentially as they first appear. The first source you cite is [1], the second is [2], and so on
• Reusing numbers: If you cite source [3] again in a later paragraph, it remains [3]
• Multiple sources in one bracket: Separate with commas or use a dash for ranges: [1], [3], [5] or [1]-[3]
• Placement: The bracketed number may appear mid-sentence or at the end of a clause, before the punctuation mark
• No author names required in text: You do not need to write the author's name in the sentence, although you may choose to for clarity, e.g., "As Smith [4] demonstrated..."

Because the reference list follows citation order, the list is not alphabetical. Reference [1] is the first source cited in the paper, reference [2] is the second, and so on.

Author Formatting Rules

IEEE author formatting differs from most other citation styles in an important way: initials come before the surname.

• Single author: J. K. Smith
• Two authors: J. K. Smith and R. L. Jones
• Three or more authors: J. K. Smith, R. L. Jones, and M. T. Brown
• Six or more authors: J. K. Smith et al. (list the first author followed by "et al.")

Note the use of initials with periods and spaces (J. K., not JK or J.K.). The first name is always reduced to initials; full first names are not used in IEEE references.

Abbreviated Journal Titles

IEEE references use abbreviated journal titles rather than writing out the full name. These abbreviations follow the standard set by the IEEE and ISO 4. For example:

If you are unsure of the correct abbreviation, check the IEEE Reference Guide or the LTWA (List of Title Word Abbreviations) maintained by the ISSN International Centre.

Worked Examples

Below are worked examples for the most common source types in IEEE style. Each example shows the numbered reference list entry and a sample in-text citation.

Journal Article

Reference entry:

[1] A. B. Chen, C. D. Patel, and E. F. Wang, "Deep learning approaches for autonomous vehicle navigation," IEEE Trans. Intell. Transp. Syst., vol. 24, no. 3, pp. 1520-1534, Mar. 2023, doi: 10.1109/TITS.2023.0001234.

In-text citation: [1]

Key formatting points: author initials before surname, article title in quotation marks with sentence-case capitalization, abbreviated and italicized journal title, volume, issue number, page range, month abbreviation, and DOI.

Conference Paper

Reference entry:

[2] R. K. Gupta and S. M. Lee, "A novel framework for real-time speech recognition in noisy environments," in Proc. IEEE Int. Conf. Acoust., Speech Signal Process. (ICASSP), Rhodes, Greece, 2023, pp. 4210-4214.

In-text citation: As demonstrated by Gupta and Lee [2], the framework achieved a 15% improvement in recognition accuracy.

Key formatting points: the conference name is abbreviated and italicized, preceded by "in" (lowercase). Include the location (city, country) and page range.

Book

Reference entry:

[3] S. Haykin, Neural Networks and Learning Machines, 3rd ed. Upper Saddle River, NJ, USA: Pearson, 2009.

In-text citation: [3]

Key formatting points: the book title is italicized and in title case. Include the edition (if not the first), the publisher location with state abbreviation and country, and the publisher name.

Book Chapter

Reference entry:

[4] L. M. Torres, "Optimization techniques for power systems," in Handbook of Electrical Engineering, R. C. Dorf, Ed. Boca Raton, FL, USA: CRC Press, 2018, pp. 45-78.

In-text citation: [4]

Key formatting points: the chapter title is in quotation marks, followed by "in" and the italicized book title. The editor is listed with "Ed." after their name.

Website

Reference entry:

[5] International Energy Agency, "Global EV Outlook 2024," IEA, Paris, France, 2024. [Online]. Available: https://www.iea.org/reports/global-ev-outlook-2024

In-text citation: [5]

Key formatting points: for websites and online reports, include the organization name as author (if applicable), the page or report title in quotation marks, the publishing body, location, and year. Add "[Online]. Available:" followed by the URL. Do not place a period after a URL.

Technical Standard

Reference entry:

[6] IEEE Standard for Information Technology - Telecommunications and Information Exchange Between Systems, IEEE Std 802.11-2020, 2021.

In-text citation: [6]

Key formatting points: the standard title is italicized. Include the standard designation number and the year of publication.

Patent

Reference entry:

[7] J. P. Robinson, "Method and apparatus for wireless power transfer," U.S. Patent 10 234 567, Mar. 19, 2019.

In-text citation: [7]

Key formatting points: patent titles are in quotation marks. Include the patent number and the issue date. The country precedes the word "Patent."

Common Mistakes to Avoid

1. Alphabetizing the reference list. IEEE references must appear in the order they are first cited, not in alphabetical order. This is one of the most frequent errors when switching from an author-date style.

1. Writing full author names. IEEE uses initials only. Write "J. K. Smith," not "John K. Smith."

1. Placing initials after the surname. In IEEE, initials come before the surname: "J. K. Smith," not "Smith, J. K." This is the opposite of APA and most other styles.

1. Forgetting to abbreviate journal titles. IEEE expects standard abbreviations for journal titles. Writing out the full title is technically incorrect, though some conference submissions are lenient about this.

1. Using author-date in-text citations. IEEE uses numbered brackets, not author-date parentheticals. Writing "(Smith, 2023)" instead of "[1]" is a style error.

1. Assigning new numbers to previously cited sources. Once a source is numbered [3], every subsequent citation of that source must also use [3]. Do not assign a new number.

1. Omitting the DOI for journal articles. When a DOI is available, include it. The DOI is the most reliable way for readers to locate the source.

Quick-Reference Table

IEEE vs. Vancouver: A Brief Comparison

IEEE and Vancouver both use numbered citation systems, which makes them easy to confuse. If you work in health sciences, you may want to read our detailed Vancouver citation guide. The main differences are:

Both styles number references in order of appearance and both produce a non-alphabetical reference list, but the formatting conventions are distinct enough that you cannot interchange them.

For a full list of supported citation styles, visit the AllCitations styles page.