| APA | P.O.. (2012, February 17). In Acronym Geek. Retrieved 02:07, February 17, 2012, from http://www.acronymgeek.com/P.O. |
| MLA | "P.O.." Acronym Geek. (2012). Acronym Geek. 17 Feb 2012 <http://www.acronymgeek.com/P.O.>. |
| MHRA | 'P.O.', Acronym Geek, 17 February 2012, <http://www.acronymgeek.com/P.O.> [accessed 17 February 2012] |
| Chicago | "P.O.", http://www.acronymgeek.com/P.O. (accessed February 17, 2012). |
| CBE/CSE | P.O. [Internet]. Acronym Geek; 2012 Feb 17 [cited 2012 Feb 17]. Available from: http://www.acronymgeek.com/P.O.. |
| Bluebook | P.O., http://www.acronymgeek.com/P.O. (last visited February 17, 2012). |
| Bluebook: Harvard JOLT | See Acronym Geek, P.O., http://www.acronymgeek.com/P.O. (optional description here) (as of Feb. 17, 2012, 02:07). |
| AMA | P.O.. Acronym Geek. February 17, 2012, 02:07. Available at: http://www.acronymgeek.com/P.O.. Accessed February 17, 2012, 02:07. |