| APA | COIO. (2012, February 15). In Acronym Geek. Retrieved 02:31, February 15, 2012, from http://www.acronymgeek.com/COIO |
| MLA | "COIO." Acronym Geek. (2012). Acronym Geek. 15 Feb 2012 <http://www.acronymgeek.com/COIO>. |
| MHRA | 'COIO', Acronym Geek, 15 February 2012, <http://www.acronymgeek.com/COIO> [accessed 15 February 2012] |
| Chicago | "COIO", http://www.acronymgeek.com/COIO (accessed February 15, 2012). |
| CBE/CSE | COIO [Internet]. Acronym Geek; 2012 Feb 15 [cited 2012 Feb 15]. Available from: http://www.acronymgeek.com/COIO. |
| Bluebook | COIO, http://www.acronymgeek.com/COIO (last visited February 15, 2012). |
| Bluebook: Harvard JOLT | See Acronym Geek, COIO, http://www.acronymgeek.com/COIO (optional description here) (as of Feb. 15, 2012, 02:31). |
| AMA | COIO. Acronym Geek. February 15, 2012, 02:31. Available at: http://www.acronymgeek.com/COIO. Accessed February 15, 2012, 02:31. |