| APA | DDI. (2012, February 13). In Acronym Geek. Retrieved 21:15, February 13, 2012, from http://www.acronymgeek.com/DDI |
| MLA | "DDI." Acronym Geek. (2012). Acronym Geek. 13 Feb 2012 <http://www.acronymgeek.com/DDI>. |
| MHRA | 'DDI', Acronym Geek, 13 February 2012, <http://www.acronymgeek.com/DDI> [accessed 13 February 2012] |
| Chicago | "DDI", http://www.acronymgeek.com/DDI (accessed February 13, 2012). |
| CBE/CSE | DDI [Internet]. Acronym Geek; 2012 Feb 13 [cited 2012 Feb 13]. Available from: http://www.acronymgeek.com/DDI. |
| Bluebook | DDI, http://www.acronymgeek.com/DDI (last visited February 13, 2012). |
| Bluebook: Harvard JOLT | See Acronym Geek, DDI, http://www.acronymgeek.com/DDI (optional description here) (as of Feb. 13, 2012, 21:15). |
| AMA | DDI. Acronym Geek. February 13, 2012, 21:15. Available at: http://www.acronymgeek.com/DDI. Accessed February 13, 2012, 21:15. |