| APA | OPOA. (2012, February 16). In Acronym Geek. Retrieved 09:49, February 16, 2012, from http://www.acronymgeek.com/OPOA |
| MLA | "OPOA." Acronym Geek. (2012). Acronym Geek. 16 Feb 2012 <http://www.acronymgeek.com/OPOA>. |
| MHRA | 'OPOA', Acronym Geek, 16 February 2012, <http://www.acronymgeek.com/OPOA> [accessed 16 February 2012] |
| Chicago | "OPOA", http://www.acronymgeek.com/OPOA (accessed February 16, 2012). |
| CBE/CSE | OPOA [Internet]. Acronym Geek; 2012 Feb 16 [cited 2012 Feb 16]. Available from: http://www.acronymgeek.com/OPOA. |
| Bluebook | OPOA, http://www.acronymgeek.com/OPOA (last visited February 16, 2012). |
| Bluebook: Harvard JOLT | See Acronym Geek, OPOA, http://www.acronymgeek.com/OPOA (optional description here) (as of Feb. 16, 2012, 09:49). |
| AMA | OPOA. Acronym Geek. February 16, 2012, 09:49. Available at: http://www.acronymgeek.com/OPOA. Accessed February 16, 2012, 09:49. |