| APA | EFK. (2012, February 14). In Acronym Geek. Retrieved 01:13, February 14, 2012, from http://www.acronymgeek.com/EFK |
| MLA | "EFK." Acronym Geek. (2012). Acronym Geek. 14 Feb 2012 <http://www.acronymgeek.com/EFK>. |
| MHRA | 'EFK', Acronym Geek, 14 February 2012, <http://www.acronymgeek.com/EFK> [accessed 14 February 2012] |
| Chicago | "EFK", http://www.acronymgeek.com/EFK (accessed February 14, 2012). |
| CBE/CSE | EFK [Internet]. Acronym Geek; 2012 Feb 14 [cited 2012 Feb 14]. Available from: http://www.acronymgeek.com/EFK. |
| Bluebook | EFK, http://www.acronymgeek.com/EFK (last visited February 14, 2012). |
| Bluebook: Harvard JOLT | See Acronym Geek, EFK, http://www.acronymgeek.com/EFK (optional description here) (as of Feb. 14, 2012, 01:13). |
| AMA | EFK. Acronym Geek. February 14, 2012, 01:13. Available at: http://www.acronymgeek.com/EFK. Accessed February 14, 2012, 01:13. |