| APA | PENG. (2012, February 17). In Acronym Geek. Retrieved 07:38, February 17, 2012, from http://www.acronymgeek.com/PENG |
| MLA | "PENG." Acronym Geek. (2012). Acronym Geek. 17 Feb 2012 <http://www.acronymgeek.com/PENG>. |
| MHRA | 'PENG', Acronym Geek, 17 February 2012, <http://www.acronymgeek.com/PENG> [accessed 17 February 2012] |
| Chicago | "PENG", http://www.acronymgeek.com/PENG (accessed February 17, 2012). |
| CBE/CSE | PENG [Internet]. Acronym Geek; 2012 Feb 17 [cited 2012 Feb 17]. Available from: http://www.acronymgeek.com/PENG. |
| Bluebook | PENG, http://www.acronymgeek.com/PENG (last visited February 17, 2012). |
| Bluebook: Harvard JOLT | See Acronym Geek, PENG, http://www.acronymgeek.com/PENG (optional description here) (as of Feb. 17, 2012, 07:38). |
| AMA | PENG. Acronym Geek. February 17, 2012, 07:38. Available at: http://www.acronymgeek.com/PENG. Accessed February 17, 2012, 07:38. |