| APA | OPOB. (2012, February 16). In Acronym Geek. Retrieved 07:41, February 16, 2012, from http://www.acronymgeek.com/OPOB |
| MLA | "OPOB." Acronym Geek. (2012). Acronym Geek. 16 Feb 2012 <http://www.acronymgeek.com/OPOB>. |
| MHRA | 'OPOB', Acronym Geek, 16 February 2012, <http://www.acronymgeek.com/OPOB> [accessed 16 February 2012] |
| Chicago | "OPOB", http://www.acronymgeek.com/OPOB (accessed February 16, 2012). |
| CBE/CSE | OPOB [Internet]. Acronym Geek; 2012 Feb 16 [cited 2012 Feb 16]. Available from: http://www.acronymgeek.com/OPOB. |
| Bluebook | OPOB, http://www.acronymgeek.com/OPOB (last visited February 16, 2012). |
| Bluebook: Harvard JOLT | See Acronym Geek, OPOB, http://www.acronymgeek.com/OPOB (optional description here) (as of Feb. 16, 2012, 07:41). |
| AMA | OPOB. Acronym Geek. February 16, 2012, 07:41. Available at: http://www.acronymgeek.com/OPOB. Accessed February 16, 2012, 07:41. |