| APA | SPNO. (2012, February 16). In Acronym Geek. Retrieved 08:22, February 16, 2012, from http://www.acronymgeek.com/SPNO |
| MLA | "SPNO." Acronym Geek. (2012). Acronym Geek. 16 Feb 2012 <http://www.acronymgeek.com/SPNO>. |
| MHRA | 'SPNO', Acronym Geek, 16 February 2012, <http://www.acronymgeek.com/SPNO> [accessed 16 February 2012] |
| Chicago | "SPNO", http://www.acronymgeek.com/SPNO (accessed February 16, 2012). |
| CBE/CSE | SPNO [Internet]. Acronym Geek; 2012 Feb 16 [cited 2012 Feb 16]. Available from: http://www.acronymgeek.com/SPNO. |
| Bluebook | SPNO, http://www.acronymgeek.com/SPNO (last visited February 16, 2012). |
| Bluebook: Harvard JOLT | See Acronym Geek, SPNO, http://www.acronymgeek.com/SPNO (optional description here) (as of Feb. 16, 2012, 08:22). |
| AMA | SPNO. Acronym Geek. February 16, 2012, 08:22. Available at: http://www.acronymgeek.com/SPNO. Accessed February 16, 2012, 08:22. |