| APA | PDEF. (2012, February 16). In Acronym Geek. Retrieved 20:24, February 16, 2012, from http://www.acronymgeek.com/PDEF |
| MLA | "PDEF." Acronym Geek. (2012). Acronym Geek. 16 Feb 2012 <http://www.acronymgeek.com/PDEF>. |
| MHRA | 'PDEF', Acronym Geek, 16 February 2012, <http://www.acronymgeek.com/PDEF> [accessed 16 February 2012] |
| Chicago | "PDEF", http://www.acronymgeek.com/PDEF (accessed February 16, 2012). |
| CBE/CSE | PDEF [Internet]. Acronym Geek; 2012 Feb 16 [cited 2012 Feb 16]. Available from: http://www.acronymgeek.com/PDEF. |
| Bluebook | PDEF, http://www.acronymgeek.com/PDEF (last visited February 16, 2012). |
| Bluebook: Harvard JOLT | See Acronym Geek, PDEF, http://www.acronymgeek.com/PDEF (optional description here) (as of Feb. 16, 2012, 20:24). |
| AMA | PDEF. Acronym Geek. February 16, 2012, 20:24. Available at: http://www.acronymgeek.com/PDEF. Accessed February 16, 2012, 20:24. |