| APA | 4Y. (2012, February 10). In Acronym Geek. Retrieved 09:39, February 10, 2012, from http://www.acronymgeek.com/4Y |
| MLA | "4Y." Acronym Geek. (2012). Acronym Geek. 10 Feb 2012 <http://www.acronymgeek.com/4Y>. |
| MHRA | '4Y', Acronym Geek, 10 February 2012, <http://www.acronymgeek.com/4Y> [accessed 10 February 2012] |
| Chicago | "4Y", http://www.acronymgeek.com/4Y (accessed February 10, 2012). |
| CBE/CSE | 4Y [Internet]. Acronym Geek; 2012 Feb 10 [cited 2012 Feb 10]. Available from: http://www.acronymgeek.com/4Y. |
| Bluebook | 4Y, http://www.acronymgeek.com/4Y (last visited February 10, 2012). |
| Bluebook: Harvard JOLT | See Acronym Geek, 4Y, http://www.acronymgeek.com/4Y (optional description here) (as of Feb. 10, 2012, 09:39). |
| AMA | 4Y. Acronym Geek. February 10, 2012, 09:39. Available at: http://www.acronymgeek.com/4Y. Accessed February 10, 2012, 09:39. |