| APA | HHA. (2012, February 13). In Acronym Geek. Retrieved 23:18, February 13, 2012, from http://www.acronymgeek.com/HHA |
| MLA | "HHA." Acronym Geek. (2012). Acronym Geek. 13 Feb 2012 <http://www.acronymgeek.com/HHA>. |
| MHRA | 'HHA', Acronym Geek, 13 February 2012, <http://www.acronymgeek.com/HHA> [accessed 13 February 2012] |
| Chicago | "HHA", http://www.acronymgeek.com/HHA (accessed February 13, 2012). |
| CBE/CSE | HHA [Internet]. Acronym Geek; 2012 Feb 13 [cited 2012 Feb 13]. Available from: http://www.acronymgeek.com/HHA. |
| Bluebook | HHA, http://www.acronymgeek.com/HHA (last visited February 13, 2012). |
| Bluebook: Harvard JOLT | See Acronym Geek, HHA, http://www.acronymgeek.com/HHA (optional description here) (as of Feb. 13, 2012, 23:18). |
| AMA | HHA. Acronym Geek. February 13, 2012, 23:18. Available at: http://www.acronymgeek.com/HHA. Accessed February 13, 2012, 23:18. |