| APA | PDDO. (2012, February 17). In Acronym Geek. Retrieved 06:45, February 17, 2012, from http://www.acronymgeek.com/PDDO |
| MLA | "PDDO." Acronym Geek. (2012). Acronym Geek. 17 Feb 2012 <http://www.acronymgeek.com/PDDO>. |
| MHRA | 'PDDO', Acronym Geek, 17 February 2012, <http://www.acronymgeek.com/PDDO> [accessed 17 February 2012] |
| Chicago | "PDDO", http://www.acronymgeek.com/PDDO (accessed February 17, 2012). |
| CBE/CSE | PDDO [Internet]. Acronym Geek; 2012 Feb 17 [cited 2012 Feb 17]. Available from: http://www.acronymgeek.com/PDDO. |
| Bluebook | PDDO, http://www.acronymgeek.com/PDDO (last visited February 17, 2012). |
| Bluebook: Harvard JOLT | See Acronym Geek, PDDO, http://www.acronymgeek.com/PDDO (optional description here) (as of Feb. 17, 2012, 06:45). |
| AMA | PDDO. Acronym Geek. February 17, 2012, 06:45. Available at: http://www.acronymgeek.com/PDDO. Accessed February 17, 2012, 06:45. |