| APA | HA. (2012, February 9). In Acronym Geek. Retrieved 13:55, February 9, 2012, from http://www.acronymgeek.com/HA |
| MLA | "HA." Acronym Geek. (2012). Acronym Geek. 9 Feb 2012 <http://www.acronymgeek.com/HA>. |
| MHRA | 'HA', Acronym Geek, 9 February 2012, <http://www.acronymgeek.com/HA> [accessed 9 February 2012] |
| Chicago | "HA", http://www.acronymgeek.com/HA (accessed February 9, 2012). |
| CBE/CSE | HA [Internet]. Acronym Geek; 2012 Feb 9 [cited 2012 Feb 9]. Available from: http://www.acronymgeek.com/HA. |
| Bluebook | HA, http://www.acronymgeek.com/HA (last visited February 9, 2012). |
| Bluebook: Harvard JOLT | See Acronym Geek, HA, http://www.acronymgeek.com/HA (optional description here) (as of Feb. 9, 2012, 13:55). |
| AMA | HA. Acronym Geek. February 9, 2012, 13:55. Available at: http://www.acronymgeek.com/HA. Accessed February 9, 2012, 13:55. |