| APA | PYS. (2012, February 10). In Acronym Geek. Retrieved 16:52, February 10, 2012, from http://www.acronymgeek.com/PYS |
| MLA | "PYS." Acronym Geek. (2012). Acronym Geek. 10 Feb 2012 <http://www.acronymgeek.com/PYS>. |
| MHRA | 'PYS', Acronym Geek, 10 February 2012, <http://www.acronymgeek.com/PYS> [accessed 10 February 2012] |
| Chicago | "PYS", http://www.acronymgeek.com/PYS (accessed February 10, 2012). |
| CBE/CSE | PYS [Internet]. Acronym Geek; 2012 Feb 10 [cited 2012 Feb 10]. Available from: http://www.acronymgeek.com/PYS. |
| Bluebook | PYS, http://www.acronymgeek.com/PYS (last visited February 10, 2012). |
| Bluebook: Harvard JOLT | See Acronym Geek, PYS, http://www.acronymgeek.com/PYS (optional description here) (as of Feb. 10, 2012, 16:52). |
| AMA | PYS. Acronym Geek. February 10, 2012, 16:52. Available at: http://www.acronymgeek.com/PYS. Accessed February 10, 2012, 16:52. |