| APA | PHFO. (2012, February 15). In Acronym Geek. Retrieved 11:43, February 15, 2012, from http://www.acronymgeek.com/PHFO |
| MLA | "PHFO." Acronym Geek. (2012). Acronym Geek. 15 Feb 2012 <http://www.acronymgeek.com/PHFO>. |
| MHRA | 'PHFO', Acronym Geek, 15 February 2012, <http://www.acronymgeek.com/PHFO> [accessed 15 February 2012] |
| Chicago | "PHFO", http://www.acronymgeek.com/PHFO (accessed February 15, 2012). |
| CBE/CSE | PHFO [Internet]. Acronym Geek; 2012 Feb 15 [cited 2012 Feb 15]. Available from: http://www.acronymgeek.com/PHFO. |
| Bluebook | PHFO, http://www.acronymgeek.com/PHFO (last visited February 15, 2012). |
| Bluebook: Harvard JOLT | See Acronym Geek, PHFO, http://www.acronymgeek.com/PHFO (optional description here) (as of Feb. 15, 2012, 11:43). |
| AMA | PHFO. Acronym Geek. February 15, 2012, 11:43. Available at: http://www.acronymgeek.com/PHFO. Accessed February 15, 2012, 11:43. |