| APA | SPDU. (2012, February 15). In Acronym Geek. Retrieved 01:38, February 15, 2012, from http://www.acronymgeek.com/SPDU |
| MLA | "SPDU." Acronym Geek. (2012). Acronym Geek. 15 Feb 2012 <http://www.acronymgeek.com/SPDU>. |
| MHRA | 'SPDU', Acronym Geek, 15 February 2012, <http://www.acronymgeek.com/SPDU> [accessed 15 February 2012] |
| Chicago | "SPDU", http://www.acronymgeek.com/SPDU (accessed February 15, 2012). |
| CBE/CSE | SPDU [Internet]. Acronym Geek; 2012 Feb 15 [cited 2012 Feb 15]. Available from: http://www.acronymgeek.com/SPDU. |
| Bluebook | SPDU, http://www.acronymgeek.com/SPDU (last visited February 15, 2012). |
| Bluebook: Harvard JOLT | See Acronym Geek, SPDU, http://www.acronymgeek.com/SPDU (optional description here) (as of Feb. 15, 2012, 01:38). |
| AMA | SPDU. Acronym Geek. February 15, 2012, 01:38. Available at: http://www.acronymgeek.com/SPDU. Accessed February 15, 2012, 01:38. |