| APA | HHHH. (2012, February 12). In Acronym Geek. Retrieved 12:46, February 12, 2012, from http://www.acronymgeek.com/HHHH |
| MLA | "HHHH." Acronym Geek. (2012). Acronym Geek. 12 Feb 2012 <http://www.acronymgeek.com/HHHH>. |
| MHRA | 'HHHH', Acronym Geek, 12 February 2012, <http://www.acronymgeek.com/HHHH> [accessed 12 February 2012] |
| Chicago | "HHHH", http://www.acronymgeek.com/HHHH (accessed February 12, 2012). |
| CBE/CSE | HHHH [Internet]. Acronym Geek; 2012 Feb 12 [cited 2012 Feb 12]. Available from: http://www.acronymgeek.com/HHHH. |
| Bluebook | HHHH, http://www.acronymgeek.com/HHHH (last visited February 12, 2012). |
| Bluebook: Harvard JOLT | See Acronym Geek, HHHH, http://www.acronymgeek.com/HHHH (optional description here) (as of Feb. 12, 2012, 12:46). |
| AMA | HHHH. Acronym Geek. February 12, 2012, 12:46. Available at: http://www.acronymgeek.com/HHHH. Accessed February 12, 2012, 12:46. |