| APA | IEI. (2012, February 14). In Acronym Geek. Retrieved 07:07, February 14, 2012, from http://www.acronymgeek.com/IEI |
| MLA | "IEI." Acronym Geek. (2012). Acronym Geek. 14 Feb 2012 <http://www.acronymgeek.com/IEI>. |
| MHRA | 'IEI', Acronym Geek, 14 February 2012, <http://www.acronymgeek.com/IEI> [accessed 14 February 2012] |
| Chicago | "IEI", http://www.acronymgeek.com/IEI (accessed February 14, 2012). |
| CBE/CSE | IEI [Internet]. Acronym Geek; 2012 Feb 14 [cited 2012 Feb 14]. Available from: http://www.acronymgeek.com/IEI. |
| Bluebook | IEI, http://www.acronymgeek.com/IEI (last visited February 14, 2012). |
| Bluebook: Harvard JOLT | See Acronym Geek, IEI, http://www.acronymgeek.com/IEI (optional description here) (as of Feb. 14, 2012, 07:07). |
| AMA | IEI. Acronym Geek. February 14, 2012, 07:07. Available at: http://www.acronymgeek.com/IEI. Accessed February 14, 2012, 07:07. |