| APA | HEF. (2012, February 14). In Acronym Geek. Retrieved 11:21, February 14, 2012, from http://www.acronymgeek.com/HEF |
| MLA | "HEF." Acronym Geek. (2012). Acronym Geek. 14 Feb 2012 <http://www.acronymgeek.com/HEF>. |
| MHRA | 'HEF', Acronym Geek, 14 February 2012, <http://www.acronymgeek.com/HEF> [accessed 14 February 2012] |
| Chicago | "HEF", http://www.acronymgeek.com/HEF (accessed February 14, 2012). |
| CBE/CSE | HEF [Internet]. Acronym Geek; 2012 Feb 14 [cited 2012 Feb 14]. Available from: http://www.acronymgeek.com/HEF. |
| Bluebook | HEF, http://www.acronymgeek.com/HEF (last visited February 14, 2012). |
| Bluebook: Harvard JOLT | See Acronym Geek, HEF, http://www.acronymgeek.com/HEF (optional description here) (as of Feb. 14, 2012, 11:21). |
| AMA | HEF. Acronym Geek. February 14, 2012, 11:21. Available at: http://www.acronymgeek.com/HEF. Accessed February 14, 2012, 11:21. |