| APA | H/O. (2012, February 9). In Acronym Geek. Retrieved 14:59, February 9, 2012, from http://www.acronymgeek.com/H/O |
| MLA | "H/O." Acronym Geek. (2012). Acronym Geek. 9 Feb 2012 <http://www.acronymgeek.com/H/O>. |
| MHRA | 'H/O', Acronym Geek, 9 February 2012, <http://www.acronymgeek.com/H/O> [accessed 9 February 2012] |
| Chicago | "H/O", http://www.acronymgeek.com/H/O (accessed February 9, 2012). |
| CBE/CSE | H/O [Internet]. Acronym Geek; 2012 Feb 9 [cited 2012 Feb 9]. Available from: http://www.acronymgeek.com/H/O. |
| Bluebook | H/O, http://www.acronymgeek.com/H/O (last visited February 9, 2012). |
| Bluebook: Harvard JOLT | See Acronym Geek, H/O, http://www.acronymgeek.com/H/O (optional description here) (as of Feb. 9, 2012, 14:59). |
| AMA | H/O. Acronym Geek. February 9, 2012, 14:59. Available at: http://www.acronymgeek.com/H/O. Accessed February 9, 2012, 14:59. |