| APA | HHDG. (2012, February 14). In Acronym Geek. Retrieved 22:45, February 14, 2012, from http://www.acronymgeek.com/HHDG |
| MLA | "HHDG." Acronym Geek. (2012). Acronym Geek. 14 Feb 2012 <http://www.acronymgeek.com/HHDG>. |
| MHRA | 'HHDG', Acronym Geek, 14 February 2012, <http://www.acronymgeek.com/HHDG> [accessed 14 February 2012] |
| Chicago | "HHDG", http://www.acronymgeek.com/HHDG (accessed February 14, 2012). |
| CBE/CSE | HHDG [Internet]. Acronym Geek; 2012 Feb 14 [cited 2012 Feb 14]. Available from: http://www.acronymgeek.com/HHDG. |
| Bluebook | HHDG, http://www.acronymgeek.com/HHDG (last visited February 14, 2012). |
| Bluebook: Harvard JOLT | See Acronym Geek, HHDG, http://www.acronymgeek.com/HHDG (optional description here) (as of Feb. 14, 2012, 22:45). |
| AMA | HHDG. Acronym Geek. February 14, 2012, 22:45. Available at: http://www.acronymgeek.com/HHDG. Accessed February 14, 2012, 22:45. |