| APA | XXO. (2012, February 13). In Acronym Geek. Retrieved 23:22, February 13, 2012, from http://www.acronymgeek.com/XXO |
| MLA | "XXO." Acronym Geek. (2012). Acronym Geek. 13 Feb 2012 <http://www.acronymgeek.com/XXO>. |
| MHRA | 'XXO', Acronym Geek, 13 February 2012, <http://www.acronymgeek.com/XXO> [accessed 13 February 2012] |
| Chicago | "XXO", http://www.acronymgeek.com/XXO (accessed February 13, 2012). |
| CBE/CSE | XXO [Internet]. Acronym Geek; 2012 Feb 13 [cited 2012 Feb 13]. Available from: http://www.acronymgeek.com/XXO. |
| Bluebook | XXO, http://www.acronymgeek.com/XXO (last visited February 13, 2012). |
| Bluebook: Harvard JOLT | See Acronym Geek, XXO, http://www.acronymgeek.com/XXO (optional description here) (as of Feb. 13, 2012, 23:22). |
| AMA | XXO. Acronym Geek. February 13, 2012, 23:22. Available at: http://www.acronymgeek.com/XXO. Accessed February 13, 2012, 23:22. |