| APA | PTB. (2012, February 13). In Acronym Geek. Retrieved 23:48, February 13, 2012, from http://www.acronymgeek.com/PTB |
| MLA | "PTB." Acronym Geek. (2012). Acronym Geek. 13 Feb 2012 <http://www.acronymgeek.com/PTB>. |
| MHRA | 'PTB', Acronym Geek, 13 February 2012, <http://www.acronymgeek.com/PTB> [accessed 13 February 2012] |
| Chicago | "PTB", http://www.acronymgeek.com/PTB (accessed February 13, 2012). |
| CBE/CSE | PTB [Internet]. Acronym Geek; 2012 Feb 13 [cited 2012 Feb 13]. Available from: http://www.acronymgeek.com/PTB. |
| Bluebook | PTB, http://www.acronymgeek.com/PTB (last visited February 13, 2012). |
| Bluebook: Harvard JOLT | See Acronym Geek, PTB, http://www.acronymgeek.com/PTB (optional description here) (as of Feb. 13, 2012, 23:48). |
| AMA | PTB. Acronym Geek. February 13, 2012, 23:48. Available at: http://www.acronymgeek.com/PTB. Accessed February 13, 2012, 23:48. |