| APA | EIO. (2012, February 13). In Acronym Geek. Retrieved 21:14, February 13, 2012, from http://www.acronymgeek.com/EIO |
| MLA | "EIO." Acronym Geek. (2012). Acronym Geek. 13 Feb 2012 <http://www.acronymgeek.com/EIO>. |
| MHRA | 'EIO', Acronym Geek, 13 February 2012, <http://www.acronymgeek.com/EIO> [accessed 13 February 2012] |
| Chicago | "EIO", http://www.acronymgeek.com/EIO (accessed February 13, 2012). |
| CBE/CSE | EIO [Internet]. Acronym Geek; 2012 Feb 13 [cited 2012 Feb 13]. Available from: http://www.acronymgeek.com/EIO. |
| Bluebook | EIO, http://www.acronymgeek.com/EIO (last visited February 13, 2012). |
| Bluebook: Harvard JOLT | See Acronym Geek, EIO, http://www.acronymgeek.com/EIO (optional description here) (as of Feb. 13, 2012, 21:14). |
| AMA | EIO. Acronym Geek. February 13, 2012, 21:14. Available at: http://www.acronymgeek.com/EIO. Accessed February 13, 2012, 21:14. |