| APA | 2O. (2012, February 10). In Acronym Geek. Retrieved 10:35, February 10, 2012, from http://www.acronymgeek.com/2O |
| MLA | "2O." Acronym Geek. (2012). Acronym Geek. 10 Feb 2012 <http://www.acronymgeek.com/2O>. |
| MHRA | '2O', Acronym Geek, 10 February 2012, <http://www.acronymgeek.com/2O> [accessed 10 February 2012] |
| Chicago | "2O", http://www.acronymgeek.com/2O (accessed February 10, 2012). |
| CBE/CSE | 2O [Internet]. Acronym Geek; 2012 Feb 10 [cited 2012 Feb 10]. Available from: http://www.acronymgeek.com/2O. |
| Bluebook | 2O, http://www.acronymgeek.com/2O (last visited February 10, 2012). |
| Bluebook: Harvard JOLT | See Acronym Geek, 2O, http://www.acronymgeek.com/2O (optional description here) (as of Feb. 10, 2012, 10:35). |
| AMA | 2O. Acronym Geek. February 10, 2012, 10:35. Available at: http://www.acronymgeek.com/2O. Accessed February 10, 2012, 10:35. |