| APA | EF. (2012, February 9). In Acronym Geek. Retrieved 14:13, February 9, 2012, from http://www.acronymgeek.com/EF |
| MLA | "EF." Acronym Geek. (2012). Acronym Geek. 9 Feb 2012 <http://www.acronymgeek.com/EF>. |
| MHRA | 'EF', Acronym Geek, 9 February 2012, <http://www.acronymgeek.com/EF> [accessed 9 February 2012] |
| Chicago | "EF", http://www.acronymgeek.com/EF (accessed February 9, 2012). |
| CBE/CSE | EF [Internet]. Acronym Geek; 2012 Feb 9 [cited 2012 Feb 9]. Available from: http://www.acronymgeek.com/EF. |
| Bluebook | EF, http://www.acronymgeek.com/EF (last visited February 9, 2012). |
| Bluebook: Harvard JOLT | See Acronym Geek, EF, http://www.acronymgeek.com/EF (optional description here) (as of Feb. 9, 2012, 14:13). |
| AMA | EF. Acronym Geek. February 9, 2012, 14:13. Available at: http://www.acronymgeek.com/EF. Accessed February 9, 2012, 14:13. |