| APA | PDDU. (2012, February 15). In Acronym Geek. Retrieved 18:57, February 15, 2012, from http://www.acronymgeek.com/PDDU |
| MLA | "PDDU." Acronym Geek. (2012). Acronym Geek. 15 Feb 2012 <http://www.acronymgeek.com/PDDU>. |
| MHRA | 'PDDU', Acronym Geek, 15 February 2012, <http://www.acronymgeek.com/PDDU> [accessed 15 February 2012] |
| Chicago | "PDDU", http://www.acronymgeek.com/PDDU (accessed February 15, 2012). |
| CBE/CSE | PDDU [Internet]. Acronym Geek; 2012 Feb 15 [cited 2012 Feb 15]. Available from: http://www.acronymgeek.com/PDDU. |
| Bluebook | PDDU, http://www.acronymgeek.com/PDDU (last visited February 15, 2012). |
| Bluebook: Harvard JOLT | See Acronym Geek, PDDU, http://www.acronymgeek.com/PDDU (optional description here) (as of Feb. 15, 2012, 18:57). |
| AMA | PDDU. Acronym Geek. February 15, 2012, 18:57. Available at: http://www.acronymgeek.com/PDDU. Accessed February 15, 2012, 18:57. |