| APA | XO. (2012, February 11). In Acronym Geek. Retrieved 21:55, February 11, 2012, from http://www.acronymgeek.com/XO |
| MLA | "XO." Acronym Geek. (2012). Acronym Geek. 11 Feb 2012 <http://www.acronymgeek.com/XO>. |
| MHRA | 'XO', Acronym Geek, 11 February 2012, <http://www.acronymgeek.com/XO> [accessed 11 February 2012] |
| Chicago | "XO", http://www.acronymgeek.com/XO (accessed February 11, 2012). |
| CBE/CSE | XO [Internet]. Acronym Geek; 2012 Feb 11 [cited 2012 Feb 11]. Available from: http://www.acronymgeek.com/XO. |
| Bluebook | XO, http://www.acronymgeek.com/XO (last visited February 11, 2012). |
| Bluebook: Harvard JOLT | See Acronym Geek, XO, http://www.acronymgeek.com/XO (optional description here) (as of Feb. 11, 2012, 21:55). |
| AMA | XO. Acronym Geek. February 11, 2012, 21:55. Available at: http://www.acronymgeek.com/XO. Accessed February 11, 2012, 21:55. |