| APA | PDDX. (2012, February 17). In Acronym Geek. Retrieved 07:57, February 17, 2012, from http://www.acronymgeek.com/PDDX |
| MLA | "PDDX." Acronym Geek. (2012). Acronym Geek. 17 Feb 2012 <http://www.acronymgeek.com/PDDX>. |
| MHRA | 'PDDX', Acronym Geek, 17 February 2012, <http://www.acronymgeek.com/PDDX> [accessed 17 February 2012] |
| Chicago | "PDDX", http://www.acronymgeek.com/PDDX (accessed February 17, 2012). |
| CBE/CSE | PDDX [Internet]. Acronym Geek; 2012 Feb 17 [cited 2012 Feb 17]. Available from: http://www.acronymgeek.com/PDDX. |
| Bluebook | PDDX, http://www.acronymgeek.com/PDDX (last visited February 17, 2012). |
| Bluebook: Harvard JOLT | See Acronym Geek, PDDX, http://www.acronymgeek.com/PDDX (optional description here) (as of Feb. 17, 2012, 07:57). |
| AMA | PDDX. Acronym Geek. February 17, 2012, 07:57. Available at: http://www.acronymgeek.com/PDDX. Accessed February 17, 2012, 07:57. |