| APA | PENE. (2012, February 14). In Acronym Geek. Retrieved 00:49, February 14, 2012, from http://www.acronymgeek.com/PENE |
| MLA | "PENE." Acronym Geek. (2012). Acronym Geek. 14 Feb 2012 <http://www.acronymgeek.com/PENE>. |
| MHRA | 'PENE', Acronym Geek, 14 February 2012, <http://www.acronymgeek.com/PENE> [accessed 14 February 2012] |
| Chicago | "PENE", http://www.acronymgeek.com/PENE (accessed February 14, 2012). |
| CBE/CSE | PENE [Internet]. Acronym Geek; 2012 Feb 14 [cited 2012 Feb 14]. Available from: http://www.acronymgeek.com/PENE. |
| Bluebook | PENE, http://www.acronymgeek.com/PENE (last visited February 14, 2012). |
| Bluebook: Harvard JOLT | See Acronym Geek, PENE, http://www.acronymgeek.com/PENE (optional description here) (as of Feb. 14, 2012, 00:49). |
| AMA | PENE. Acronym Geek. February 14, 2012, 00:49. Available at: http://www.acronymgeek.com/PENE. Accessed February 14, 2012, 00:49. |