| APA | APEI. (2012, February 14). In Acronym Geek. Retrieved 23:26, February 14, 2012, from http://www.acronymgeek.com/APEI |
| MLA | "APEI." Acronym Geek. (2012). Acronym Geek. 14 Feb 2012 <http://www.acronymgeek.com/APEI>. |
| MHRA | 'APEI', Acronym Geek, 14 February 2012, <http://www.acronymgeek.com/APEI> [accessed 14 February 2012] |
| Chicago | "APEI", http://www.acronymgeek.com/APEI (accessed February 14, 2012). |
| CBE/CSE | APEI [Internet]. Acronym Geek; 2012 Feb 14 [cited 2012 Feb 14]. Available from: http://www.acronymgeek.com/APEI. |
| Bluebook | APEI, http://www.acronymgeek.com/APEI (last visited February 14, 2012). |
| Bluebook: Harvard JOLT | See Acronym Geek, APEI, http://www.acronymgeek.com/APEI (optional description here) (as of Feb. 14, 2012, 23:26). |
| AMA | APEI. Acronym Geek. February 14, 2012, 23:26. Available at: http://www.acronymgeek.com/APEI. Accessed February 14, 2012, 23:26. |