| APA | OIPI. (2012, February 15). In Acronym Geek. Retrieved 23:11, February 15, 2012, from http://www.acronymgeek.com/OIPI |
| MLA | "OIPI." Acronym Geek. (2012). Acronym Geek. 15 Feb 2012 <http://www.acronymgeek.com/OIPI>. |
| MHRA | 'OIPI', Acronym Geek, 15 February 2012, <http://www.acronymgeek.com/OIPI> [accessed 15 February 2012] |
| Chicago | "OIPI", http://www.acronymgeek.com/OIPI (accessed February 15, 2012). |
| CBE/CSE | OIPI [Internet]. Acronym Geek; 2012 Feb 15 [cited 2012 Feb 15]. Available from: http://www.acronymgeek.com/OIPI. |
| Bluebook | OIPI, http://www.acronymgeek.com/OIPI (last visited February 15, 2012). |
| Bluebook: Harvard JOLT | See Acronym Geek, OIPI, http://www.acronymgeek.com/OIPI (optional description here) (as of Feb. 15, 2012, 23:11). |
| AMA | OIPI. Acronym Geek. February 15, 2012, 23:11. Available at: http://www.acronymgeek.com/OIPI. Accessed February 15, 2012, 23:11. |