| APA | HIOL. (2012, February 16). In Acronym Geek. Retrieved 21:38, February 16, 2012, from http://www.acronymgeek.com/HIOL |
| MLA | "HIOL." Acronym Geek. (2012). Acronym Geek. 16 Feb 2012 <http://www.acronymgeek.com/HIOL>. |
| MHRA | 'HIOL', Acronym Geek, 16 February 2012, <http://www.acronymgeek.com/HIOL> [accessed 16 February 2012] |
| Chicago | "HIOL", http://www.acronymgeek.com/HIOL (accessed February 16, 2012). |
| CBE/CSE | HIOL [Internet]. Acronym Geek; 2012 Feb 16 [cited 2012 Feb 16]. Available from: http://www.acronymgeek.com/HIOL. |
| Bluebook | HIOL, http://www.acronymgeek.com/HIOL (last visited February 16, 2012). |
| Bluebook: Harvard JOLT | See Acronym Geek, HIOL, http://www.acronymgeek.com/HIOL (optional description here) (as of Feb. 16, 2012, 21:38). |
| AMA | HIOL. Acronym Geek. February 16, 2012, 21:38. Available at: http://www.acronymgeek.com/HIOL. Accessed February 16, 2012, 21:38. |