| APA | SDEF. (2012, February 16). In Acronym Geek. Retrieved 21:55, February 16, 2012, from http://www.acronymgeek.com/SDEF |
| MLA | "SDEF." Acronym Geek. (2012). Acronym Geek. 16 Feb 2012 <http://www.acronymgeek.com/SDEF>. |
| MHRA | 'SDEF', Acronym Geek, 16 February 2012, <http://www.acronymgeek.com/SDEF> [accessed 16 February 2012] |
| Chicago | "SDEF", http://www.acronymgeek.com/SDEF (accessed February 16, 2012). |
| CBE/CSE | SDEF [Internet]. Acronym Geek; 2012 Feb 16 [cited 2012 Feb 16]. Available from: http://www.acronymgeek.com/SDEF. |
| Bluebook | SDEF, http://www.acronymgeek.com/SDEF (last visited February 16, 2012). |
| Bluebook: Harvard JOLT | See Acronym Geek, SDEF, http://www.acronymgeek.com/SDEF (optional description here) (as of Feb. 16, 2012, 21:55). |
| AMA | SDEF. Acronym Geek. February 16, 2012, 21:55. Available at: http://www.acronymgeek.com/SDEF. Accessed February 16, 2012, 21:55. |