| APA | PTU. (2012, February 13). In Acronym Geek. Retrieved 21:09, February 13, 2012, from http://www.acronymgeek.com/PTU |
| MLA | "PTU." Acronym Geek. (2012). Acronym Geek. 13 Feb 2012 <http://www.acronymgeek.com/PTU>. |
| MHRA | 'PTU', Acronym Geek, 13 February 2012, <http://www.acronymgeek.com/PTU> [accessed 13 February 2012] |
| Chicago | "PTU", http://www.acronymgeek.com/PTU (accessed February 13, 2012). |
| CBE/CSE | PTU [Internet]. Acronym Geek; 2012 Feb 13 [cited 2012 Feb 13]. Available from: http://www.acronymgeek.com/PTU. |
| Bluebook | PTU, http://www.acronymgeek.com/PTU (last visited February 13, 2012). |
| Bluebook: Harvard JOLT | See Acronym Geek, PTU, http://www.acronymgeek.com/PTU (optional description here) (as of Feb. 13, 2012, 21:09). |
| AMA | PTU. Acronym Geek. February 13, 2012, 21:09. Available at: http://www.acronymgeek.com/PTU. Accessed February 13, 2012, 21:09. |