| APA | 4. (2012, February 9). In Acronym Geek. Retrieved 17:22, February 9, 2012, from http://www.acronymgeek.com/4 |
| MLA | "4." Acronym Geek. (2012). Acronym Geek. 9 Feb 2012 <http://www.acronymgeek.com/4>. |
| MHRA | '4', Acronym Geek, 9 February 2012, <http://www.acronymgeek.com/4> [accessed 9 February 2012] |
| Chicago | "4", http://www.acronymgeek.com/4 (accessed February 9, 2012). |
| CBE/CSE | 4 [Internet]. Acronym Geek; 2012 Feb 9 [cited 2012 Feb 9]. Available from: http://www.acronymgeek.com/4. |
| Bluebook | 4, http://www.acronymgeek.com/4 (last visited February 9, 2012). |
| Bluebook: Harvard JOLT | See Acronym Geek, 4, http://www.acronymgeek.com/4 (optional description here) (as of Feb. 9, 2012, 17:22). |
| AMA | 4. Acronym Geek. February 9, 2012, 17:22. Available at: http://www.acronymgeek.com/4. Accessed February 9, 2012, 17:22. |