| APA | HHGS. (2012, February 14). In Acronym Geek. Retrieved 18:05, February 14, 2012, from http://www.acronymgeek.com/HHGS |
| MLA | "HHGS." Acronym Geek. (2012). Acronym Geek. 14 Feb 2012 <http://www.acronymgeek.com/HHGS>. |
| MHRA | 'HHGS', Acronym Geek, 14 February 2012, <http://www.acronymgeek.com/HHGS> [accessed 14 February 2012] |
| Chicago | "HHGS", http://www.acronymgeek.com/HHGS (accessed February 14, 2012). |
| CBE/CSE | HHGS [Internet]. Acronym Geek; 2012 Feb 14 [cited 2012 Feb 14]. Available from: http://www.acronymgeek.com/HHGS. |
| Bluebook | HHGS, http://www.acronymgeek.com/HHGS (last visited February 14, 2012). |
| Bluebook: Harvard JOLT | See Acronym Geek, HHGS, http://www.acronymgeek.com/HHGS (optional description here) (as of Feb. 14, 2012, 18:05). |
| AMA | HHGS. Acronym Geek. February 14, 2012, 18:05. Available at: http://www.acronymgeek.com/HHGS. Accessed February 14, 2012, 18:05. |