| APA | SOPN. (2012, February 11). In Acronym Geek. Retrieved 21:14, February 11, 2012, from http://www.acronymgeek.com/SOPN |
| MLA | "SOPN." Acronym Geek. (2012). Acronym Geek. 11 Feb 2012 <http://www.acronymgeek.com/SOPN>. |
| MHRA | 'SOPN', Acronym Geek, 11 February 2012, <http://www.acronymgeek.com/SOPN> [accessed 11 February 2012] |
| Chicago | "SOPN", http://www.acronymgeek.com/SOPN (accessed February 11, 2012). |
| CBE/CSE | SOPN [Internet]. Acronym Geek; 2012 Feb 11 [cited 2012 Feb 11]. Available from: http://www.acronymgeek.com/SOPN. |
| Bluebook | SOPN, http://www.acronymgeek.com/SOPN (last visited February 11, 2012). |
| Bluebook: Harvard JOLT | See Acronym Geek, SOPN, http://www.acronymgeek.com/SOPN (optional description here) (as of Feb. 11, 2012, 21:14). |
| AMA | SOPN. Acronym Geek. February 11, 2012, 21:14. Available at: http://www.acronymgeek.com/SOPN. Accessed February 11, 2012, 21:14. |