| APA | HXO. (2012, February 14). In Acronym Geek. Retrieved 20:40, February 14, 2012, from http://www.acronymgeek.com/HXO |
| MLA | "HXO." Acronym Geek. (2012). Acronym Geek. 14 Feb 2012 <http://www.acronymgeek.com/HXO>. |
| MHRA | 'HXO', Acronym Geek, 14 February 2012, <http://www.acronymgeek.com/HXO> [accessed 14 February 2012] |
| Chicago | "HXO", http://www.acronymgeek.com/HXO (accessed February 14, 2012). |
| CBE/CSE | HXO [Internet]. Acronym Geek; 2012 Feb 14 [cited 2012 Feb 14]. Available from: http://www.acronymgeek.com/HXO. |
| Bluebook | HXO, http://www.acronymgeek.com/HXO (last visited February 14, 2012). |
| Bluebook: Harvard JOLT | See Acronym Geek, HXO, http://www.acronymgeek.com/HXO (optional description here) (as of Feb. 14, 2012, 20:40). |
| AMA | HXO. Acronym Geek. February 14, 2012, 20:40. Available at: http://www.acronymgeek.com/HXO. Accessed February 14, 2012, 20:40. |