| APA | SOP. (2012, February 9). In Acronym Geek. Retrieved 20:29, February 9, 2012, from http://www.acronymgeek.com/SOP |
| MLA | "SOP." Acronym Geek. (2012). Acronym Geek. 9 Feb 2012 <http://www.acronymgeek.com/SOP>. |
| MHRA | 'SOP', Acronym Geek, 9 February 2012, <http://www.acronymgeek.com/SOP> [accessed 9 February 2012] |
| Chicago | "SOP", http://www.acronymgeek.com/SOP (accessed February 9, 2012). |
| CBE/CSE | SOP [Internet]. Acronym Geek; 2012 Feb 9 [cited 2012 Feb 9]. Available from: http://www.acronymgeek.com/SOP. |
| Bluebook | SOP, http://www.acronymgeek.com/SOP (last visited February 9, 2012). |
| Bluebook: Harvard JOLT | See Acronym Geek, SOP, http://www.acronymgeek.com/SOP (optional description here) (as of Feb. 9, 2012, 20:29). |
| AMA | SOP. Acronym Geek. February 9, 2012, 20:29. Available at: http://www.acronymgeek.com/SOP. Accessed February 9, 2012, 20:29. |