IEEE Referencing: Citing sources in the text

Citing sources in the text

IEEE in-text citations consist of numbers provided in square brackets, which correspond to the appropriate sources in the reference list at the end of the paper.

The in-text citations numbers start at [1] and continue in ascending order throughout the paper – unless you are referring to a source you have already cited in your text, in which case you can use the previously assigned number.  

Each in-text citation number should be enclosed by square brackets and appear on the text line, inside sentence punctuation, with a space before the bracket, e.g.

 Thevenin’s and Norton’s theorems are widely used for circuit analysis simplification [13].

Citations of references may be given simply as “in [1]...”, rather than as “in reference [1] ...”.

Furthermore, citations may be grammatically treated either as if they were:

  • footnote numbers, e.g.

As shown by Jones [4] [5] …

For more details, see [1], [3], [7].

as mentioned earlier [3], [4]­, [5], [6], [8] …

Taylor et al. [5] have noted …

  • or nouns:

As seen in [2] …

According to [4] and [6], [7], and [8] …

In contrast to [5, p. 7], it is evident that…

As demonstrated in [4] …

When authors are mentioned, they may be treated in the following way:

Rickard [5] has shown …

Jones [6], and Zheng and Rogers [7] have stated …

Azzarello et al. [3] stated that they were unable to determine why …

If there are more than three authors, provide et al. (meaning ‘and others') after the first author in the text of the paper. In the reference list, however, list all the authors for up to six authors– use et al. only if the names are not given. Also use et al. in the reference list for more than 6 authors, e.g.:

[8]    J. D. Bellamy et al., Computer Telephony Integration, New York: Wiley, 2010.

Do not mention the authors of a source or provide the date of publication within the text (e.g. “in Jones [1]” should be changed to “in [1]”) except in such cases where the author’s name is integral to the understanding of the sentence (e.g. “Jones [1] proposed a new approach for sensor and actuator selection problems).

Editing the in-text citation numbers may require renumbering the whole reference list. Please check that the in-text citation numbers match the reference list numbers.

Single citation in the text 

Various approaches have been followed in the design of microwave circuits [7].

According to [5], there is a little evidence that …

In [3], the resulting composite video signal was presented …

… as previously shown [7].

… as shown by Jones [6].

Use et al. when three or more names are given in a reference cited in the source:

as shown by Taylor and Smith [5];

as shown by Ripka et al. [6]

Multiple citations in the text

The preferred method of citing more than one source at a time is listing each citation number separately with a comma or dash between each citation:

[1], [3], [7]

[6], [7], and [8]


as shown by Taylor [4] and Smith and Ripka [5];

It is noted that multiple sources can also be provided in the following way as seen in some literature:

Considerable body of work on electrical circuits [1], [3], [6], [7], [8], [10], [14], [15], and [16] defines ...

Citing the same source multiple times

If you want to refer to a previous reference, do not provide a new citation number, nor use ‘ibid.’ (meaning ‘the same’) or ‘op. cit.’ (meaning ‘the work cited’) terms. If you want to refer to the same source twice or multiple times, simply repeat the earlier citation number and then use that same number in all subsequent citations throughout the body of the paper.

The separate instances of referring to the same source should be made in text, for example, when referring to another fact, idea or an opinion found within the same source at different page numbers, use the following forms: [2, pp. 3-5], [5, eq. (2)] for referring to an equation, [5, Sec. IV] a section, [5, Tab. 3] a table, [1, Ch. 2] a chapter, etc.