| APA | 999. (2012, February 12). In Acronym Geek. Retrieved 06:53, February 12, 2012, from http://www.acronymgeek.com/999 |
| MLA | "999." Acronym Geek. (2012). Acronym Geek. 12 Feb 2012 <http://www.acronymgeek.com/999>. |
| MHRA | '999', Acronym Geek, 12 February 2012, <http://www.acronymgeek.com/999> [accessed 12 February 2012] |
| Chicago | "999", http://www.acronymgeek.com/999 (accessed February 12, 2012). |
| CBE/CSE | 999 [Internet]. Acronym Geek; 2012 Feb 12 [cited 2012 Feb 12]. Available from: http://www.acronymgeek.com/999. |
| Bluebook | 999, http://www.acronymgeek.com/999 (last visited February 12, 2012). |
| Bluebook: Harvard JOLT | See Acronym Geek, 999, http://www.acronymgeek.com/999 (optional description here) (as of Feb. 12, 2012, 06:53). |
| AMA | 999. Acronym Geek. February 12, 2012, 06:53. Available at: http://www.acronymgeek.com/999. Accessed February 12, 2012, 06:53. |