| APA | EFR. (2012, February 14). In Acronym Geek. Retrieved 02:10, February 14, 2012, from http://www.acronymgeek.com/EFR |
| MLA | "EFR." Acronym Geek. (2012). Acronym Geek. 14 Feb 2012 <http://www.acronymgeek.com/EFR>. |
| MHRA | 'EFR', Acronym Geek, 14 February 2012, <http://www.acronymgeek.com/EFR> [accessed 14 February 2012] |
| Chicago | "EFR", http://www.acronymgeek.com/EFR (accessed February 14, 2012). |
| CBE/CSE | EFR [Internet]. Acronym Geek; 2012 Feb 14 [cited 2012 Feb 14]. Available from: http://www.acronymgeek.com/EFR. |
| Bluebook | EFR, http://www.acronymgeek.com/EFR (last visited February 14, 2012). |
| Bluebook: Harvard JOLT | See Acronym Geek, EFR, http://www.acronymgeek.com/EFR (optional description here) (as of Feb. 14, 2012, 02:10). |
| AMA | EFR. Acronym Geek. February 14, 2012, 02:10. Available at: http://www.acronymgeek.com/EFR. Accessed February 14, 2012, 02:10. |