| APA | ESO. (2012, February 14). In Acronym Geek. Retrieved 20:41, February 14, 2012, from http://www.acronymgeek.com/ESO |
| MLA | "ESO." Acronym Geek. (2012). Acronym Geek. 14 Feb 2012 <http://www.acronymgeek.com/ESO>. |
| MHRA | 'ESO', Acronym Geek, 14 February 2012, <http://www.acronymgeek.com/ESO> [accessed 14 February 2012] |
| Chicago | "ESO", http://www.acronymgeek.com/ESO (accessed February 14, 2012). |
| CBE/CSE | ESO [Internet]. Acronym Geek; 2012 Feb 14 [cited 2012 Feb 14]. Available from: http://www.acronymgeek.com/ESO. |
| Bluebook | ESO, http://www.acronymgeek.com/ESO (last visited February 14, 2012). |
| Bluebook: Harvard JOLT | See Acronym Geek, ESO, http://www.acronymgeek.com/ESO (optional description here) (as of Feb. 14, 2012, 20:41). |
| AMA | ESO. Acronym Geek. February 14, 2012, 20:41. Available at: http://www.acronymgeek.com/ESO. Accessed February 14, 2012, 20:41. |