| APA | APPROX. (2012, February 12). In Acronym Geek. Retrieved 13:06, February 12, 2012, from http://www.acronymgeek.com/APPROX |
| MLA | "APPROX." Acronym Geek. (2012). Acronym Geek. 12 Feb 2012 <http://www.acronymgeek.com/APPROX>. |
| MHRA | 'APPROX', Acronym Geek, 12 February 2012, <http://www.acronymgeek.com/APPROX> [accessed 12 February 2012] |
| Chicago | "APPROX", http://www.acronymgeek.com/APPROX (accessed February 12, 2012). |
| CBE/CSE | APPROX [Internet]. Acronym Geek; 2012 Feb 12 [cited 2012 Feb 12]. Available from: http://www.acronymgeek.com/APPROX. |
| Bluebook | APPROX, http://www.acronymgeek.com/APPROX (last visited February 12, 2012). |
| Bluebook: Harvard JOLT | See Acronym Geek, APPROX, http://www.acronymgeek.com/APPROX (optional description here) (as of Feb. 12, 2012, 13:06). |
| AMA | APPROX. Acronym Geek. February 12, 2012, 13:06. Available at: http://www.acronymgeek.com/APPROX. Accessed February 12, 2012, 13:06. |