| APA | E4P. (2012, February 11). In Acronym Geek. Retrieved 22:55, February 11, 2012, from http://www.acronymgeek.com/E4P |
| MLA | "E4P." Acronym Geek. (2012). Acronym Geek. 11 Feb 2012 <http://www.acronymgeek.com/E4P>. |
| MHRA | 'E4P', Acronym Geek, 11 February 2012, <http://www.acronymgeek.com/E4P> [accessed 11 February 2012] |
| Chicago | "E4P", http://www.acronymgeek.com/E4P (accessed February 11, 2012). |
| CBE/CSE | E4P [Internet]. Acronym Geek; 2012 Feb 11 [cited 2012 Feb 11]. Available from: http://www.acronymgeek.com/E4P. |
| Bluebook | E4P, http://www.acronymgeek.com/E4P (last visited February 11, 2012). |
| Bluebook: Harvard JOLT | See Acronym Geek, E4P, http://www.acronymgeek.com/E4P (optional description here) (as of Feb. 11, 2012, 22:55). |
| AMA | E4P. Acronym Geek. February 11, 2012, 22:55. Available at: http://www.acronymgeek.com/E4P. Accessed February 11, 2012, 22:55. |