| APA | OPWO. (2012, February 15). In Acronym Geek. Retrieved 04:12, February 15, 2012, from http://www.acronymgeek.com/OPWO |
| MLA | "OPWO." Acronym Geek. (2012). Acronym Geek. 15 Feb 2012 <http://www.acronymgeek.com/OPWO>. |
| MHRA | 'OPWO', Acronym Geek, 15 February 2012, <http://www.acronymgeek.com/OPWO> [accessed 15 February 2012] |
| Chicago | "OPWO", http://www.acronymgeek.com/OPWO (accessed February 15, 2012). |
| CBE/CSE | OPWO [Internet]. Acronym Geek; 2012 Feb 15 [cited 2012 Feb 15]. Available from: http://www.acronymgeek.com/OPWO. |
| Bluebook | OPWO, http://www.acronymgeek.com/OPWO (last visited February 15, 2012). |
| Bluebook: Harvard JOLT | See Acronym Geek, OPWO, http://www.acronymgeek.com/OPWO (optional description here) (as of Feb. 15, 2012, 04:12). |
| AMA | OPWO. Acronym Geek. February 15, 2012, 04:12. Available at: http://www.acronymgeek.com/OPWO. Accessed February 15, 2012, 04:12. |