| APA | COS. (2012, February 14). In Acronym Geek. Retrieved 09:24, February 14, 2012, from http://www.acronymgeek.com/COS |
| MLA | "COS." Acronym Geek. (2012). Acronym Geek. 14 Feb 2012 <http://www.acronymgeek.com/COS>. |
| MHRA | 'COS', Acronym Geek, 14 February 2012, <http://www.acronymgeek.com/COS> [accessed 14 February 2012] |
| Chicago | "COS", http://www.acronymgeek.com/COS (accessed February 14, 2012). |
| CBE/CSE | COS [Internet]. Acronym Geek; 2012 Feb 14 [cited 2012 Feb 14]. Available from: http://www.acronymgeek.com/COS. |
| Bluebook | COS, http://www.acronymgeek.com/COS (last visited February 14, 2012). |
| Bluebook: Harvard JOLT | See Acronym Geek, COS, http://www.acronymgeek.com/COS (optional description here) (as of Feb. 14, 2012, 09:24). |
| AMA | COS. Acronym Geek. February 14, 2012, 09:24. Available at: http://www.acronymgeek.com/COS. Accessed February 14, 2012, 09:24. |