| APA | OTPN. (2012, February 17). In Acronym Geek. Retrieved 08:20, February 17, 2012, from http://www.acronymgeek.com/OTPN |
| MLA | "OTPN." Acronym Geek. (2012). Acronym Geek. 17 Feb 2012 <http://www.acronymgeek.com/OTPN>. |
| MHRA | 'OTPN', Acronym Geek, 17 February 2012, <http://www.acronymgeek.com/OTPN> [accessed 17 February 2012] |
| Chicago | "OTPN", http://www.acronymgeek.com/OTPN (accessed February 17, 2012). |
| CBE/CSE | OTPN [Internet]. Acronym Geek; 2012 Feb 17 [cited 2012 Feb 17]. Available from: http://www.acronymgeek.com/OTPN. |
| Bluebook | OTPN, http://www.acronymgeek.com/OTPN (last visited February 17, 2012). |
| Bluebook: Harvard JOLT | See Acronym Geek, OTPN, http://www.acronymgeek.com/OTPN (optional description here) (as of Feb. 17, 2012, 08:20). |
| AMA | OTPN. Acronym Geek. February 17, 2012, 08:20. Available at: http://www.acronymgeek.com/OTPN. Accessed February 17, 2012, 08:20. |