| APA | OPNV. (2012, February 17). In Acronym Geek. Retrieved 08:05, February 17, 2012, from http://www.acronymgeek.com/OPNV |
| MLA | "OPNV." Acronym Geek. (2012). Acronym Geek. 17 Feb 2012 <http://www.acronymgeek.com/OPNV>. |
| MHRA | 'OPNV', Acronym Geek, 17 February 2012, <http://www.acronymgeek.com/OPNV> [accessed 17 February 2012] |
| Chicago | "OPNV", http://www.acronymgeek.com/OPNV (accessed February 17, 2012). |
| CBE/CSE | OPNV [Internet]. Acronym Geek; 2012 Feb 17 [cited 2012 Feb 17]. Available from: http://www.acronymgeek.com/OPNV. |
| Bluebook | OPNV, http://www.acronymgeek.com/OPNV (last visited February 17, 2012). |
| Bluebook: Harvard JOLT | See Acronym Geek, OPNV, http://www.acronymgeek.com/OPNV (optional description here) (as of Feb. 17, 2012, 08:05). |
| AMA | OPNV. Acronym Geek. February 17, 2012, 08:05. Available at: http://www.acronymgeek.com/OPNV. Accessed February 17, 2012, 08:05. |