| APA | OPSD. (2012, February 14). In Acronym Geek. Retrieved 14:39, February 14, 2012, from http://www.acronymgeek.com/OPSD |
| MLA | "OPSD." Acronym Geek. (2012). Acronym Geek. 14 Feb 2012 <http://www.acronymgeek.com/OPSD>. |
| MHRA | 'OPSD', Acronym Geek, 14 February 2012, <http://www.acronymgeek.com/OPSD> [accessed 14 February 2012] |
| Chicago | "OPSD", http://www.acronymgeek.com/OPSD (accessed February 14, 2012). |
| CBE/CSE | OPSD [Internet]. Acronym Geek; 2012 Feb 14 [cited 2012 Feb 14]. Available from: http://www.acronymgeek.com/OPSD. |
| Bluebook | OPSD, http://www.acronymgeek.com/OPSD (last visited February 14, 2012). |
| Bluebook: Harvard JOLT | See Acronym Geek, OPSD, http://www.acronymgeek.com/OPSD (optional description here) (as of Feb. 14, 2012, 14:39). |
| AMA | OPSD. Acronym Geek. February 14, 2012, 14:39. Available at: http://www.acronymgeek.com/OPSD. Accessed February 14, 2012, 14:39. |