| APA | GREF. (2012, February 16). In Acronym Geek. Retrieved 04:34, February 16, 2012, from http://www.acronymgeek.com/GREF |
| MLA | "GREF." Acronym Geek. (2012). Acronym Geek. 16 Feb 2012 <http://www.acronymgeek.com/GREF>. |
| MHRA | 'GREF', Acronym Geek, 16 February 2012, <http://www.acronymgeek.com/GREF> [accessed 16 February 2012] |
| Chicago | "GREF", http://www.acronymgeek.com/GREF (accessed February 16, 2012). |
| CBE/CSE | GREF [Internet]. Acronym Geek; 2012 Feb 16 [cited 2012 Feb 16]. Available from: http://www.acronymgeek.com/GREF. |
| Bluebook | GREF, http://www.acronymgeek.com/GREF (last visited February 16, 2012). |
| Bluebook: Harvard JOLT | See Acronym Geek, GREF, http://www.acronymgeek.com/GREF (optional description here) (as of Feb. 16, 2012, 04:34). |
| AMA | GREF. Acronym Geek. February 16, 2012, 04:34. Available at: http://www.acronymgeek.com/GREF. Accessed February 16, 2012, 04:34. |