| APA | C4. (2012, February 14). In Acronym Geek. Retrieved 06:07, February 14, 2012, from http://www.acronymgeek.com/C4 |
| MLA | "C4." Acronym Geek. (2012). Acronym Geek. 14 Feb 2012 <http://www.acronymgeek.com/C4>. |
| MHRA | 'C4', Acronym Geek, 14 February 2012, <http://www.acronymgeek.com/C4> [accessed 14 February 2012] |
| Chicago | "C4", http://www.acronymgeek.com/C4 (accessed February 14, 2012). |
| CBE/CSE | C4 [Internet]. Acronym Geek; 2012 Feb 14 [cited 2012 Feb 14]. Available from: http://www.acronymgeek.com/C4. |
| Bluebook | C4, http://www.acronymgeek.com/C4 (last visited February 14, 2012). |
| Bluebook: Harvard JOLT | See Acronym Geek, C4, http://www.acronymgeek.com/C4 (optional description here) (as of Feb. 14, 2012, 06:07). |
| AMA | C4. Acronym Geek. February 14, 2012, 06:07. Available at: http://www.acronymgeek.com/C4. Accessed February 14, 2012, 06:07. |