| APA | QO. (2012, February 14). In Acronym Geek. Retrieved 06:16, February 14, 2012, from http://www.acronymgeek.com/QO |
| MLA | "QO." Acronym Geek. (2012). Acronym Geek. 14 Feb 2012 <http://www.acronymgeek.com/QO>. |
| MHRA | 'QO', Acronym Geek, 14 February 2012, <http://www.acronymgeek.com/QO> [accessed 14 February 2012] |
| Chicago | "QO", http://www.acronymgeek.com/QO (accessed February 14, 2012). |
| CBE/CSE | QO [Internet]. Acronym Geek; 2012 Feb 14 [cited 2012 Feb 14]. Available from: http://www.acronymgeek.com/QO. |
| Bluebook | QO, http://www.acronymgeek.com/QO (last visited February 14, 2012). |
| Bluebook: Harvard JOLT | See Acronym Geek, QO, http://www.acronymgeek.com/QO (optional description here) (as of Feb. 14, 2012, 06:16). |
| AMA | QO. Acronym Geek. February 14, 2012, 06:16. Available at: http://www.acronymgeek.com/QO. Accessed February 14, 2012, 06:16. |