| APA | OPRU. (2012, February 15). In Acronym Geek. Retrieved 20:20, February 15, 2012, from http://www.acronymgeek.com/OPRU |
| MLA | "OPRU." Acronym Geek. (2012). Acronym Geek. 15 Feb 2012 <http://www.acronymgeek.com/OPRU>. |
| MHRA | 'OPRU', Acronym Geek, 15 February 2012, <http://www.acronymgeek.com/OPRU> [accessed 15 February 2012] |
| Chicago | "OPRU", http://www.acronymgeek.com/OPRU (accessed February 15, 2012). |
| CBE/CSE | OPRU [Internet]. Acronym Geek; 2012 Feb 15 [cited 2012 Feb 15]. Available from: http://www.acronymgeek.com/OPRU. |
| Bluebook | OPRU, http://www.acronymgeek.com/OPRU (last visited February 15, 2012). |
| Bluebook: Harvard JOLT | See Acronym Geek, OPRU, http://www.acronymgeek.com/OPRU (optional description here) (as of Feb. 15, 2012, 20:20). |
| AMA | OPRU. Acronym Geek. February 15, 2012, 20:20. Available at: http://www.acronymgeek.com/OPRU. Accessed February 15, 2012, 20:20. |