| APA | ZDO. (2012, February 13). In Acronym Geek. Retrieved 23:31, February 13, 2012, from http://www.acronymgeek.com/ZDO |
| MLA | "ZDO." Acronym Geek. (2012). Acronym Geek. 13 Feb 2012 <http://www.acronymgeek.com/ZDO>. |
| MHRA | 'ZDO', Acronym Geek, 13 February 2012, <http://www.acronymgeek.com/ZDO> [accessed 13 February 2012] |
| Chicago | "ZDO", http://www.acronymgeek.com/ZDO (accessed February 13, 2012). |
| CBE/CSE | ZDO [Internet]. Acronym Geek; 2012 Feb 13 [cited 2012 Feb 13]. Available from: http://www.acronymgeek.com/ZDO. |
| Bluebook | ZDO, http://www.acronymgeek.com/ZDO (last visited February 13, 2012). |
| Bluebook: Harvard JOLT | See Acronym Geek, ZDO, http://www.acronymgeek.com/ZDO (optional description here) (as of Feb. 13, 2012, 23:31). |
| AMA | ZDO. Acronym Geek. February 13, 2012, 23:31. Available at: http://www.acronymgeek.com/ZDO. Accessed February 13, 2012, 23:31. |