| APA | OEIO. (2012, February 16). In Acronym Geek. Retrieved 08:15, February 16, 2012, from http://www.acronymgeek.com/OEIO |
| MLA | "OEIO." Acronym Geek. (2012). Acronym Geek. 16 Feb 2012 <http://www.acronymgeek.com/OEIO>. |
| MHRA | 'OEIO', Acronym Geek, 16 February 2012, <http://www.acronymgeek.com/OEIO> [accessed 16 February 2012] |
| Chicago | "OEIO", http://www.acronymgeek.com/OEIO (accessed February 16, 2012). |
| CBE/CSE | OEIO [Internet]. Acronym Geek; 2012 Feb 16 [cited 2012 Feb 16]. Available from: http://www.acronymgeek.com/OEIO. |
| Bluebook | OEIO, http://www.acronymgeek.com/OEIO (last visited February 16, 2012). |
| Bluebook: Harvard JOLT | See Acronym Geek, OEIO, http://www.acronymgeek.com/OEIO (optional description here) (as of Feb. 16, 2012, 08:15). |
| AMA | OEIO. Acronym Geek. February 16, 2012, 08:15. Available at: http://www.acronymgeek.com/OEIO. Accessed February 16, 2012, 08:15. |