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Information Literacy Skills for Research (Engineering): Citation Styles


There are many citation styles available, depending on the academic discipline involved. Some commonly used citation styles include APA, Chicago, Harvard and IEEE.  

Check with your supervisors, professors, departments, faculty, conference organizers or publishers to find out their preferred citation style.

To learn more about the major citation styles, refer to Citation Styles Guide.

6 Key Rules to IEEE Citation Style

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Citation Styles

CDE Graduate Programmes Guidelines

Some guidelines on references are given in the Handbook for Research Students (M.Eng./Ph.D.) found on MyPortal@NUS > College of Design and Engineering > Graduate Students > Student Handbook. You may want to check with your supervisor/department for their preferred citation styles as well.

In-text Citation & Bibliography

You cite the references you used by inserting:

  • In-text citation :: this appears within a sentence, e.g. author-date, numbered and footnotes
  • Bibliography/references :: this appears at the end of the document

Depending on the information sources (e.g. books, books chapters, articles, conference papers, theses, patents, Internet resources) and citation style you use, the format and elements of the in-text citation and bibliography would vary.

Some main elements of a citation are:

  • Author(s)
  • Book Chapter Title or Journal Article Title
  • Book Title or Journal Title
  • Year of Publication
  • Volume or Issue Numbering
  • Page Numbering

Citing or acknowledging information sources used is not limited to writing only.  It applies to outputs in all formats, e.g. presentations, posters, video clips.

As mentioned, there are various commonly used citation styles, e.g. APA, Chicago, Harvard and IEEE. The formatting used in each style is slightly different. The example below illustrates how this particular journal article would be listed in the references section for each citation style.

Source: American Physical Society

  Authors   Yang Liu, Yifan Liu, Mengji Chen, Shalabh Srivastava, Pan He, Kie Leong Teo, Timothy Phung, See-Hun Yang, Hyunsoo Yang
  Date   December 2019
  Title   Current-induced out-of-plane spin accumulation on the (001) surface of the IrMN3 antiferromagnet
  Journal   Physical Review Applied
  Specifics     Volume: 12; Issue: 6; Pages: 064046-1-064046-9; Doi: 10.1103/PhysRevApplied.12.064046  

APA 7th ed.

Liu, Y., Liu, Y., Chen, M., Srivastava, S., He, P., Teo, K. L., Phung, T., Yang, S.-H., & Yang, H. (2019). Current-induced out-of-plane spin accumulation on the (001) surface of the IrMN3 antiferromagnet. Physical Review Applied, 12(6), 064046-1-064046-9.  


Liu, Yang, Yifan Liu, Mengji Chen, Shalabh Srivastava, He Pan, Kie Leong Teo, Timothy Phung, See-Hun Yang, Hyunsoo Yang. 2019. “Current-induced out-of-plane spin accumulation on the (001) surface of the IrMN3 antiferromagnet.” Physical Review Applied 12(6). American Physical Society: 064046-1–9.  


Liu, Y., Liu, Y., Chen, M., Srivastava, S., He, P., Teo, K. L., Phung, T., Yang, S.-H., and Yang, H. (2019) 'Current-induced out-of-plane spin accumulation on the (001) surface of the IrMN3 antiferromagnet', Physical Review Letters, 12(6) [online]. Available at: (Accessed: 19 April 2023) 


[1] Y. Liu, Y. Liu, M. Chen, S. Srivastava, P. He, K. L. Teo, T. Phung, S.-H. Yang and H. Yang, Current-induced out-of-plane spin accumulation on the (001) surface of the IrMN3 antiferromagnet,” Phys. Rev. Appl., vol. 12, no. 6, pp. 064046-1–064046-9, Dec. 2019., doi: 10.1103/PhysRevApplied.12.064046.

To learn how to cite using IEEE Citation Style, refer to the reference guide available on the Citation Styles Guide > IEEE tab.

To understand the components of a citation, refer to the "Citation Styles" tab.

To view the common citation mistakes made and avoid making them, refer to the "Common IEEE Citation Mistakes" tab.

Below are some examples of information sources cited using IEEE citation style:

Books / E-books

[1]  B. Klaus and P. Horn, Robot Vision. Cambridge, MA, USA: MIT Press, 1986.

[2]  A. Solanki, A. Nayyar and M. Naved, Eds., Generative Adversarial Networks for Image-to-image Translation. London: Academic Print, 2021. [Online]. Available: 

Book Chapters

[3]  L. Stein, “Random patterns,” in Computers and You, J. S. Brake, Ed. New York, NY, USA:Wiley, 1994, pp. 55-70.

Journals Articles / Periodicals


[4]  G. E. Hinton, S. Osindero and Y. W. Teh, "A fast learning algorithm for deep belief nets," Neural Comput., vol. 18, No. 7, pp. 1527-1554, Jul. 2006.


[5]  W. P. Risk, G. S. Kino, and H. J. Shaw, "Fiber-optic frequency shifter using a surface acoustic wave incident at an oblique angle," Opt. Lett., vol. 11, no. 2, pp. 115-117, Feb. 1986 [Online]. Available:

(with DOI)

[6]  A. Thean and J.-P. Leburton, “Flash memory: towards single electronics,” IEEE Potentials, vol. 21, no. 4, pp. 35-40, Dec. 2002, doi: 10.1109/MP.2002.1044216.


Conference Proceedings (Online)

[7]  X. Chen and K. Zhang, "Extending blockchain functionality with statechain," in 2017 IEEE 23rd Int. Conf. Parallel and Distrib. Syst., Shen Zhen, China Dec. 2017, pp. 240-247. [Online]. Available from IEEE Xplore Digital Library.


Conference Papers 


[8]  V. Chandrasekaran, S. Sanghavi, P. A. Parrilo, and A. S. Willsky. (2009). Sparse and low-rank matrix decompositions. Presented at IFAC 2009. [Online]. Available:

(Paper presented at a Conference)

[9]  J. Arrillaga and B. Giessner, "Limitation of short-circuit levels by means of HDVC," presented at the IEEE Summer Power Meeting, Los Angeles, CA, USA, Jul. 12-17, 1990, Paper 70 CP637.


Magazines Articles

[10]  S. Fujii and Y. Mikami. (1991, Apr. 20). Construction aspects of intelligent buildings. IEEE Commun. Mag. [CD-ROM]. pp.50-57. Available: UMI File: IPO (IEEE/IEE Publications Ondisc) Item: 3939837

Technical Reports

[11]  P. Diament, S. L. Richert, and W. L. Lupatkin, “V-line surface-wave radiation and scanning,” Dept. Elect. Eng., Columbia Univ., New York, Sci. Rep. 85, Aug. 1991.

Patents (Online)

[12]  Screwless clip mounted computer drive, by D. Williams. (2005, Apr. 26). U.S. Patent 6,885,550 [Online]. Available:     



[13]  Letter Symbols for Quantities, ANSI Standard Y10.5-1968.

[14] Sustainable Data Centres - Part 1: Energy and Environmental Management Systems, SS 564-1, 2020. [Online]. Available:

[15] Secondary Lithium Batteries for Light EV (Electric Vehicle) Applications. General Safety Requirements and Test Methods, BS EN 50604-1, 2016. [Online]. Available:



[16]  J. O. Williams, “Narrow-band analyzer,” Ph.D. dissertation, Dept. Elect. Eng., Harvard Univ., Cambridge, MA, 1993.



(With author)

[17]  P. Norman, “U.S. unleashes military to fight fake news, disinformation.", (accessed Sep. 2, 2019). 

(No author)

[18] Machine learning helps EV batteries to charge in 10 minutes." The Engineer., (accessed Aug. 25, 2022). 

Tracing incomplete or incorrect citations waste the reader’s time and effort.  The following are some common errors made in IEEE citation style when citing journal articles and conference papers:

Multiple Authors and Format

1. Cite author name using the format [Initials] [Family Name].

  Authors   Xin Kang; Ying-Chang Liang; Arumugam Nallanathan; Hari Krishna Garg; Peter J. Smith; Tuck Sing Terence Siew
  Incorrectly cited as    Kang, X., Liang, Y. C., Nallanathan, A., Garg H.K., Smith, P. J. and Terence Siew, T. S.
  Correctly cited as   X. Kang, Y. C. Liang, A. Nallanathan, H. K. Garg, P. J. Smith and T. S. T. Siew.


2. For more than 6 authors, use et al.

  Authors   BaoYu Zong; YuPing Wu ; Pin Ho ; Nguyen Nguyen Phuoc ; Yong Yang ; ZaiBing Guo ; Shan Zheng Ang ; ZhiHong Yang ; ZhengWen Li 
  Incorrectly cited as    B. Zong, Y. Wu, P. Ho, N. N. Phuoc, Y. Yang, Z. Guo, S. Z. Ang, Z. Yang and Z. Li.
  Correctly cited as   B. Zong et al.


3. The article title should be enclosed within quotes “” and there is a comma before the closed quote ”.


[24] L. Liu, R. Zhang and K. C. Chua, "Wireless information transfer with opportunistic energy harvesting," IEEE Trans. Wireless Commun., vol. 12, no. 1, pp. 288-300, Jan. 2013.

4. Take note of punctuation and symbols used for volume, issue, page numbering, month as well as the final full stop, i.e. 

vol. x, no. x, pp. xxx-xxx, Abbrev. Month, year.


[25] H . Eriksson and P. E. Danielsson, “Two problems on Boolean memories,” IEEE Trans. Electron. Devicesvol. EC-16, no. 3, pp. 364–365, Jun. 1967.

[26] P. Dely, A. Kassler and N. Bayer, "OpenFlow for wireless mesh networks," Proc. 20th Int. Conf. Comput. Commun. Networks, 2011, pp. 1-6.

Take note of the position of the year and absence of page numbering for citing (unpublished) papers presented at conferences.


5. Create a hanging indent for each reference with the bracketed numbers flush with the left side of the page. The hanging indent highlights the numerical sequence of your references.


[27] S. Azodolmolky et al., "Experimental demonstration of an impairment aware network planning and operation tool
=> for transparent/translucent optical networks,” J. Lightw. Technol., vol. 29, no. 4, pp. 439–448, Sep. 2011. 

Capitalization of Article Title and Journal Title

6. Capitalize only the first word of the title of an article, paper or book chapter


Parametric oscillators and nonlinear materials,”

7. Capitalize and italicize the (major) word in the title of a book, journal or conference proceedings. Abbreviate journal and conference proceedings.

Example 1

Super-Resolution Restoration and Image Reconstruction for Passive Millimeter Wave Imaging

Example 2

Proc. 20th Int. Conf. Comput. Commun. Networks