| APA | KPEN. (2012, February 15). In Acronym Geek. Retrieved 13:50, February 15, 2012, from http://www.acronymgeek.com/KPEN |
| MLA | "KPEN." Acronym Geek. (2012). Acronym Geek. 15 Feb 2012 <http://www.acronymgeek.com/KPEN>. |
| MHRA | 'KPEN', Acronym Geek, 15 February 2012, <http://www.acronymgeek.com/KPEN> [accessed 15 February 2012] |
| Chicago | "KPEN", http://www.acronymgeek.com/KPEN (accessed February 15, 2012). |
| CBE/CSE | KPEN [Internet]. Acronym Geek; 2012 Feb 15 [cited 2012 Feb 15]. Available from: http://www.acronymgeek.com/KPEN. |
| Bluebook | KPEN, http://www.acronymgeek.com/KPEN (last visited February 15, 2012). |
| Bluebook: Harvard JOLT | See Acronym Geek, KPEN, http://www.acronymgeek.com/KPEN (optional description here) (as of Feb. 15, 2012, 13:50). |
| AMA | KPEN. Acronym Geek. February 15, 2012, 13:50. Available at: http://www.acronymgeek.com/KPEN. Accessed February 15, 2012, 13:50. |