| APA | UDK. (2012, February 14). In Acronym Geek. Retrieved 02:08, February 14, 2012, from http://www.acronymgeek.com/UDK |
| MLA | "UDK." Acronym Geek. (2012). Acronym Geek. 14 Feb 2012 <http://www.acronymgeek.com/UDK>. |
| MHRA | 'UDK', Acronym Geek, 14 February 2012, <http://www.acronymgeek.com/UDK> [accessed 14 February 2012] |
| Chicago | "UDK", http://www.acronymgeek.com/UDK (accessed February 14, 2012). |
| CBE/CSE | UDK [Internet]. Acronym Geek; 2012 Feb 14 [cited 2012 Feb 14]. Available from: http://www.acronymgeek.com/UDK. |
| Bluebook | UDK, http://www.acronymgeek.com/UDK (last visited February 14, 2012). |
| Bluebook: Harvard JOLT | See Acronym Geek, UDK, http://www.acronymgeek.com/UDK (optional description here) (as of Feb. 14, 2012, 02:08). |
| AMA | UDK. Acronym Geek. February 14, 2012, 02:08. Available at: http://www.acronymgeek.com/UDK. Accessed February 14, 2012, 02:08. |