| APA | APO. (2012, February 9). In Acronym Geek. Retrieved 21:11, February 9, 2012, from http://www.acronymgeek.com/APO |
| MLA | "APO." Acronym Geek. (2012). Acronym Geek. 9 Feb 2012 <http://www.acronymgeek.com/APO>. |
| MHRA | 'APO', Acronym Geek, 9 February 2012, <http://www.acronymgeek.com/APO> [accessed 9 February 2012] |
| Chicago | "APO", http://www.acronymgeek.com/APO (accessed February 9, 2012). |
| CBE/CSE | APO [Internet]. Acronym Geek; 2012 Feb 9 [cited 2012 Feb 9]. Available from: http://www.acronymgeek.com/APO. |
| Bluebook | APO, http://www.acronymgeek.com/APO (last visited February 9, 2012). |
| Bluebook: Harvard JOLT | See Acronym Geek, APO, http://www.acronymgeek.com/APO (optional description here) (as of Feb. 9, 2012, 21:11). |
| AMA | APO. Acronym Geek. February 9, 2012, 21:11. Available at: http://www.acronymgeek.com/APO. Accessed February 9, 2012, 21:11. |