| APA | PPE. (2012, February 9). In Acronym Geek. Retrieved 20:54, February 9, 2012, from http://www.acronymgeek.com/PPE |
| MLA | "PPE." Acronym Geek. (2012). Acronym Geek. 9 Feb 2012 <http://www.acronymgeek.com/PPE>. |
| MHRA | 'PPE', Acronym Geek, 9 February 2012, <http://www.acronymgeek.com/PPE> [accessed 9 February 2012] |
| Chicago | "PPE", http://www.acronymgeek.com/PPE (accessed February 9, 2012). |
| CBE/CSE | PPE [Internet]. Acronym Geek; 2012 Feb 9 [cited 2012 Feb 9]. Available from: http://www.acronymgeek.com/PPE. |
| Bluebook | PPE, http://www.acronymgeek.com/PPE (last visited February 9, 2012). |
| Bluebook: Harvard JOLT | See Acronym Geek, PPE, http://www.acronymgeek.com/PPE (optional description here) (as of Feb. 9, 2012, 20:54). |
| AMA | PPE. Acronym Geek. February 9, 2012, 20:54. Available at: http://www.acronymgeek.com/PPE. Accessed February 9, 2012, 20:54. |