| APA | A2O. (2012, February 12). In Acronym Geek. Retrieved 06:57, February 12, 2012, from http://www.acronymgeek.com/A2O |
| MLA | "A2O." Acronym Geek. (2012). Acronym Geek. 12 Feb 2012 <http://www.acronymgeek.com/A2O>. |
| MHRA | 'A2O', Acronym Geek, 12 February 2012, <http://www.acronymgeek.com/A2O> [accessed 12 February 2012] |
| Chicago | "A2O", http://www.acronymgeek.com/A2O (accessed February 12, 2012). |
| CBE/CSE | A2O [Internet]. Acronym Geek; 2012 Feb 12 [cited 2012 Feb 12]. Available from: http://www.acronymgeek.com/A2O. |
| Bluebook | A2O, http://www.acronymgeek.com/A2O (last visited February 12, 2012). |
| Bluebook: Harvard JOLT | See Acronym Geek, A2O, http://www.acronymgeek.com/A2O (optional description here) (as of Feb. 12, 2012, 06:57). |
| AMA | A2O. Acronym Geek. February 12, 2012, 06:57. Available at: http://www.acronymgeek.com/A2O. Accessed February 12, 2012, 06:57. |