| APA | 4E. (2012, February 11). In Acronym Geek. Retrieved 21:54, February 11, 2012, from http://www.acronymgeek.com/4E |
| MLA | "4E." Acronym Geek. (2012). Acronym Geek. 11 Feb 2012 <http://www.acronymgeek.com/4E>. |
| MHRA | '4E', Acronym Geek, 11 February 2012, <http://www.acronymgeek.com/4E> [accessed 11 February 2012] |
| Chicago | "4E", http://www.acronymgeek.com/4E (accessed February 11, 2012). |
| CBE/CSE | 4E [Internet]. Acronym Geek; 2012 Feb 11 [cited 2012 Feb 11]. Available from: http://www.acronymgeek.com/4E. |
| Bluebook | 4E, http://www.acronymgeek.com/4E (last visited February 11, 2012). |
| Bluebook: Harvard JOLT | See Acronym Geek, 4E, http://www.acronymgeek.com/4E (optional description here) (as of Feb. 11, 2012, 21:54). |
| AMA | 4E. Acronym Geek. February 11, 2012, 21:54. Available at: http://www.acronymgeek.com/4E. Accessed February 11, 2012, 21:54. |