| APA | OTPK. (2012, February 15). In Acronym Geek. Retrieved 18:33, February 15, 2012, from http://www.acronymgeek.com/OTPK |
| MLA | "OTPK." Acronym Geek. (2012). Acronym Geek. 15 Feb 2012 <http://www.acronymgeek.com/OTPK>. |
| MHRA | 'OTPK', Acronym Geek, 15 February 2012, <http://www.acronymgeek.com/OTPK> [accessed 15 February 2012] |
| Chicago | "OTPK", http://www.acronymgeek.com/OTPK (accessed February 15, 2012). |
| CBE/CSE | OTPK [Internet]. Acronym Geek; 2012 Feb 15 [cited 2012 Feb 15]. Available from: http://www.acronymgeek.com/OTPK. |
| Bluebook | OTPK, http://www.acronymgeek.com/OTPK (last visited February 15, 2012). |
| Bluebook: Harvard JOLT | See Acronym Geek, OTPK, http://www.acronymgeek.com/OTPK (optional description here) (as of Feb. 15, 2012, 18:33). |
| AMA | OTPK. Acronym Geek. February 15, 2012, 18:33. Available at: http://www.acronymgeek.com/OTPK. Accessed February 15, 2012, 18:33. |