| APA | PSFO. (2012, February 15). In Acronym Geek. Retrieved 12:20, February 15, 2012, from http://www.acronymgeek.com/PSFO |
| MLA | "PSFO." Acronym Geek. (2012). Acronym Geek. 15 Feb 2012 <http://www.acronymgeek.com/PSFO>. |
| MHRA | 'PSFO', Acronym Geek, 15 February 2012, <http://www.acronymgeek.com/PSFO> [accessed 15 February 2012] |
| Chicago | "PSFO", http://www.acronymgeek.com/PSFO (accessed February 15, 2012). |
| CBE/CSE | PSFO [Internet]. Acronym Geek; 2012 Feb 15 [cited 2012 Feb 15]. Available from: http://www.acronymgeek.com/PSFO. |
| Bluebook | PSFO, http://www.acronymgeek.com/PSFO (last visited February 15, 2012). |
| Bluebook: Harvard JOLT | See Acronym Geek, PSFO, http://www.acronymgeek.com/PSFO (optional description here) (as of Feb. 15, 2012, 12:20). |
| AMA | PSFO. Acronym Geek. February 15, 2012, 12:20. Available at: http://www.acronymgeek.com/PSFO. Accessed February 15, 2012, 12:20. |