| APA | OPUM. (2012, February 14). In Acronym Geek. Retrieved 00:44, February 14, 2012, from http://www.acronymgeek.com/OPUM |
| MLA | "OPUM." Acronym Geek. (2012). Acronym Geek. 14 Feb 2012 <http://www.acronymgeek.com/OPUM>. |
| MHRA | 'OPUM', Acronym Geek, 14 February 2012, <http://www.acronymgeek.com/OPUM> [accessed 14 February 2012] |
| Chicago | "OPUM", http://www.acronymgeek.com/OPUM (accessed February 14, 2012). |
| CBE/CSE | OPUM [Internet]. Acronym Geek; 2012 Feb 14 [cited 2012 Feb 14]. Available from: http://www.acronymgeek.com/OPUM. |
| Bluebook | OPUM, http://www.acronymgeek.com/OPUM (last visited February 14, 2012). |
| Bluebook: Harvard JOLT | See Acronym Geek, OPUM, http://www.acronymgeek.com/OPUM (optional description here) (as of Feb. 14, 2012, 00:44). |
| AMA | OPUM. Acronym Geek. February 14, 2012, 00:44. Available at: http://www.acronymgeek.com/OPUM. Accessed February 14, 2012, 00:44. |