| APA | QHO4. (2012, February 11). In Acronym Geek. Retrieved 22:12, February 11, 2012, from http://www.acronymgeek.com/QHO4 |
| MLA | "QHO4." Acronym Geek. (2012). Acronym Geek. 11 Feb 2012 <http://www.acronymgeek.com/QHO4>. |
| MHRA | 'QHO4', Acronym Geek, 11 February 2012, <http://www.acronymgeek.com/QHO4> [accessed 11 February 2012] |
| Chicago | "QHO4", http://www.acronymgeek.com/QHO4 (accessed February 11, 2012). |
| CBE/CSE | QHO4 [Internet]. Acronym Geek; 2012 Feb 11 [cited 2012 Feb 11]. Available from: http://www.acronymgeek.com/QHO4. |
| Bluebook | QHO4, http://www.acronymgeek.com/QHO4 (last visited February 11, 2012). |
| Bluebook: Harvard JOLT | See Acronym Geek, QHO4, http://www.acronymgeek.com/QHO4 (optional description here) (as of Feb. 11, 2012, 22:12). |
| AMA | QHO4. Acronym Geek. February 11, 2012, 22:12. Available at: http://www.acronymgeek.com/QHO4. Accessed February 11, 2012, 22:12. |