| APA | SPF. (2012, February 14). In Acronym Geek. Retrieved 07:56, February 14, 2012, from http://www.acronymgeek.com/SPF |
| MLA | "SPF." Acronym Geek. (2012). Acronym Geek. 14 Feb 2012 <http://www.acronymgeek.com/SPF>. |
| MHRA | 'SPF', Acronym Geek, 14 February 2012, <http://www.acronymgeek.com/SPF> [accessed 14 February 2012] |
| Chicago | "SPF", http://www.acronymgeek.com/SPF (accessed February 14, 2012). |
| CBE/CSE | SPF [Internet]. Acronym Geek; 2012 Feb 14 [cited 2012 Feb 14]. Available from: http://www.acronymgeek.com/SPF. |
| Bluebook | SPF, http://www.acronymgeek.com/SPF (last visited February 14, 2012). |
| Bluebook: Harvard JOLT | See Acronym Geek, SPF, http://www.acronymgeek.com/SPF (optional description here) (as of Feb. 14, 2012, 07:56). |
| AMA | SPF. Acronym Geek. February 14, 2012, 07:56. Available at: http://www.acronymgeek.com/SPF. Accessed February 14, 2012, 07:56. |