| APA | OPVI. (2012, February 14). In Acronym Geek. Retrieved 08:06, February 14, 2012, from http://www.acronymgeek.com/OPVI |
| MLA | "OPVI." Acronym Geek. (2012). Acronym Geek. 14 Feb 2012 <http://www.acronymgeek.com/OPVI>. |
| MHRA | 'OPVI', Acronym Geek, 14 February 2012, <http://www.acronymgeek.com/OPVI> [accessed 14 February 2012] |
| Chicago | "OPVI", http://www.acronymgeek.com/OPVI (accessed February 14, 2012). |
| CBE/CSE | OPVI [Internet]. Acronym Geek; 2012 Feb 14 [cited 2012 Feb 14]. Available from: http://www.acronymgeek.com/OPVI. |
| Bluebook | OPVI, http://www.acronymgeek.com/OPVI (last visited February 14, 2012). |
| Bluebook: Harvard JOLT | See Acronym Geek, OPVI, http://www.acronymgeek.com/OPVI (optional description here) (as of Feb. 14, 2012, 08:06). |
| AMA | OPVI. Acronym Geek. February 14, 2012, 08:06. Available at: http://www.acronymgeek.com/OPVI. Accessed February 14, 2012, 08:06. |