| APA | HIOI. (2012, February 15). In Acronym Geek. Retrieved 10:09, February 15, 2012, from http://www.acronymgeek.com/HIOI |
| MLA | "HIOI." Acronym Geek. (2012). Acronym Geek. 15 Feb 2012 <http://www.acronymgeek.com/HIOI>. |
| MHRA | 'HIOI', Acronym Geek, 15 February 2012, <http://www.acronymgeek.com/HIOI> [accessed 15 February 2012] |
| Chicago | "HIOI", http://www.acronymgeek.com/HIOI (accessed February 15, 2012). |
| CBE/CSE | HIOI [Internet]. Acronym Geek; 2012 Feb 15 [cited 2012 Feb 15]. Available from: http://www.acronymgeek.com/HIOI. |
| Bluebook | HIOI, http://www.acronymgeek.com/HIOI (last visited February 15, 2012). |
| Bluebook: Harvard JOLT | See Acronym Geek, HIOI, http://www.acronymgeek.com/HIOI (optional description here) (as of Feb. 15, 2012, 10:09). |
| AMA | HIOI. Acronym Geek. February 15, 2012, 10:09. Available at: http://www.acronymgeek.com/HIOI. Accessed February 15, 2012, 10:09. |