| APA | GEI. (2012, February 15). In Acronym Geek. Retrieved 03:37, February 15, 2012, from http://www.acronymgeek.com/GEI |
| MLA | "GEI." Acronym Geek. (2012). Acronym Geek. 15 Feb 2012 <http://www.acronymgeek.com/GEI>. |
| MHRA | 'GEI', Acronym Geek, 15 February 2012, <http://www.acronymgeek.com/GEI> [accessed 15 February 2012] |
| Chicago | "GEI", http://www.acronymgeek.com/GEI (accessed February 15, 2012). |
| CBE/CSE | GEI [Internet]. Acronym Geek; 2012 Feb 15 [cited 2012 Feb 15]. Available from: http://www.acronymgeek.com/GEI. |
| Bluebook | GEI, http://www.acronymgeek.com/GEI (last visited February 15, 2012). |
| Bluebook: Harvard JOLT | See Acronym Geek, GEI, http://www.acronymgeek.com/GEI (optional description here) (as of Feb. 15, 2012, 03:37). |
| AMA | GEI. Acronym Geek. February 15, 2012, 03:37. Available at: http://www.acronymgeek.com/GEI. Accessed February 15, 2012, 03:37. |