| APA | X4X. (2012, February 14). In Acronym Geek. Retrieved 01:12, February 14, 2012, from http://www.acronymgeek.com/X4X |
| MLA | "X4X." Acronym Geek. (2012). Acronym Geek. 14 Feb 2012 <http://www.acronymgeek.com/X4X>. |
| MHRA | 'X4X', Acronym Geek, 14 February 2012, <http://www.acronymgeek.com/X4X> [accessed 14 February 2012] |
| Chicago | "X4X", http://www.acronymgeek.com/X4X (accessed February 14, 2012). |
| CBE/CSE | X4X [Internet]. Acronym Geek; 2012 Feb 14 [cited 2012 Feb 14]. Available from: http://www.acronymgeek.com/X4X. |
| Bluebook | X4X, http://www.acronymgeek.com/X4X (last visited February 14, 2012). |
| Bluebook: Harvard JOLT | See Acronym Geek, X4X, http://www.acronymgeek.com/X4X (optional description here) (as of Feb. 14, 2012, 01:12). |
| AMA | X4X. Acronym Geek. February 14, 2012, 01:12. Available at: http://www.acronymgeek.com/X4X. Accessed February 14, 2012, 01:12. |