| APA | OPOF. (2012, February 16). In Acronym Geek. Retrieved 02:06, February 16, 2012, from http://www.acronymgeek.com/OPOF |
| MLA | "OPOF." Acronym Geek. (2012). Acronym Geek. 16 Feb 2012 <http://www.acronymgeek.com/OPOF>. |
| MHRA | 'OPOF', Acronym Geek, 16 February 2012, <http://www.acronymgeek.com/OPOF> [accessed 16 February 2012] |
| Chicago | "OPOF", http://www.acronymgeek.com/OPOF (accessed February 16, 2012). |
| CBE/CSE | OPOF [Internet]. Acronym Geek; 2012 Feb 16 [cited 2012 Feb 16]. Available from: http://www.acronymgeek.com/OPOF. |
| Bluebook | OPOF, http://www.acronymgeek.com/OPOF (last visited February 16, 2012). |
| Bluebook: Harvard JOLT | See Acronym Geek, OPOF, http://www.acronymgeek.com/OPOF (optional description here) (as of Feb. 16, 2012, 02:06). |
| AMA | OPOF. Acronym Geek. February 16, 2012, 02:06. Available at: http://www.acronymgeek.com/OPOF. Accessed February 16, 2012, 02:06. |