| APA | CLEO. (2012, February 16). In Acronym Geek. Retrieved 08:28, February 16, 2012, from http://www.acronymgeek.com/CLEO |
| MLA | "CLEO." Acronym Geek. (2012). Acronym Geek. 16 Feb 2012 <http://www.acronymgeek.com/CLEO>. |
| MHRA | 'CLEO', Acronym Geek, 16 February 2012, <http://www.acronymgeek.com/CLEO> [accessed 16 February 2012] |
| Chicago | "CLEO", http://www.acronymgeek.com/CLEO (accessed February 16, 2012). |
| CBE/CSE | CLEO [Internet]. Acronym Geek; 2012 Feb 16 [cited 2012 Feb 16]. Available from: http://www.acronymgeek.com/CLEO. |
| Bluebook | CLEO, http://www.acronymgeek.com/CLEO (last visited February 16, 2012). |
| Bluebook: Harvard JOLT | See Acronym Geek, CLEO, http://www.acronymgeek.com/CLEO (optional description here) (as of Feb. 16, 2012, 08:28). |
| AMA | CLEO. Acronym Geek. February 16, 2012, 08:28. Available at: http://www.acronymgeek.com/CLEO. Accessed February 16, 2012, 08:28. |