| APA | PTAO. (2012, February 17). In Acronym Geek. Retrieved 00:48, February 17, 2012, from http://www.acronymgeek.com/PTAO |
| MLA | "PTAO." Acronym Geek. (2012). Acronym Geek. 17 Feb 2012 <http://www.acronymgeek.com/PTAO>. |
| MHRA | 'PTAO', Acronym Geek, 17 February 2012, <http://www.acronymgeek.com/PTAO> [accessed 17 February 2012] |
| Chicago | "PTAO", http://www.acronymgeek.com/PTAO (accessed February 17, 2012). |
| CBE/CSE | PTAO [Internet]. Acronym Geek; 2012 Feb 17 [cited 2012 Feb 17]. Available from: http://www.acronymgeek.com/PTAO. |
| Bluebook | PTAO, http://www.acronymgeek.com/PTAO (last visited February 17, 2012). |
| Bluebook: Harvard JOLT | See Acronym Geek, PTAO, http://www.acronymgeek.com/PTAO (optional description here) (as of Feb. 17, 2012, 00:48). |
| AMA | PTAO. Acronym Geek. February 17, 2012, 00:48. Available at: http://www.acronymgeek.com/PTAO. Accessed February 17, 2012, 00:48. |