| APA | C4K. (2012, February 14). In Acronym Geek. Retrieved 19:14, February 14, 2012, from http://www.acronymgeek.com/C4K |
| MLA | "C4K." Acronym Geek. (2012). Acronym Geek. 14 Feb 2012 <http://www.acronymgeek.com/C4K>. |
| MHRA | 'C4K', Acronym Geek, 14 February 2012, <http://www.acronymgeek.com/C4K> [accessed 14 February 2012] |
| Chicago | "C4K", http://www.acronymgeek.com/C4K (accessed February 14, 2012). |
| CBE/CSE | C4K [Internet]. Acronym Geek; 2012 Feb 14 [cited 2012 Feb 14]. Available from: http://www.acronymgeek.com/C4K. |
| Bluebook | C4K, http://www.acronymgeek.com/C4K (last visited February 14, 2012). |
| Bluebook: Harvard JOLT | See Acronym Geek, C4K, http://www.acronymgeek.com/C4K (optional description here) (as of Feb. 14, 2012, 19:14). |
| AMA | C4K. Acronym Geek. February 14, 2012, 19:14. Available at: http://www.acronymgeek.com/C4K. Accessed February 14, 2012, 19:14. |