| APA | HOS. (2012, February 10). In Acronym Geek. Retrieved 11:16, February 10, 2012, from http://www.acronymgeek.com/HOS |
| MLA | "HOS." Acronym Geek. (2012). Acronym Geek. 10 Feb 2012 <http://www.acronymgeek.com/HOS>. |
| MHRA | 'HOS', Acronym Geek, 10 February 2012, <http://www.acronymgeek.com/HOS> [accessed 10 February 2012] |
| Chicago | "HOS", http://www.acronymgeek.com/HOS (accessed February 10, 2012). |
| CBE/CSE | HOS [Internet]. Acronym Geek; 2012 Feb 10 [cited 2012 Feb 10]. Available from: http://www.acronymgeek.com/HOS. |
| Bluebook | HOS, http://www.acronymgeek.com/HOS (last visited February 10, 2012). |
| Bluebook: Harvard JOLT | See Acronym Geek, HOS, http://www.acronymgeek.com/HOS (optional description here) (as of Feb. 10, 2012, 11:16). |
| AMA | HOS. Acronym Geek. February 10, 2012, 11:16. Available at: http://www.acronymgeek.com/HOS. Accessed February 10, 2012, 11:16. |