| APA | UDC. (2012, February 14). In Acronym Geek. Retrieved 02:29, February 14, 2012, from http://www.acronymgeek.com/UDC |
| MLA | "UDC." Acronym Geek. (2012). Acronym Geek. 14 Feb 2012 <http://www.acronymgeek.com/UDC>. |
| MHRA | 'UDC', Acronym Geek, 14 February 2012, <http://www.acronymgeek.com/UDC> [accessed 14 February 2012] |
| Chicago | "UDC", http://www.acronymgeek.com/UDC (accessed February 14, 2012). |
| CBE/CSE | UDC [Internet]. Acronym Geek; 2012 Feb 14 [cited 2012 Feb 14]. Available from: http://www.acronymgeek.com/UDC. |
| Bluebook | UDC, http://www.acronymgeek.com/UDC (last visited February 14, 2012). |
| Bluebook: Harvard JOLT | See Acronym Geek, UDC, http://www.acronymgeek.com/UDC (optional description here) (as of Feb. 14, 2012, 02:29). |
| AMA | UDC. Acronym Geek. February 14, 2012, 02:29. Available at: http://www.acronymgeek.com/UDC. Accessed February 14, 2012, 02:29. |