| APA | LPEN. (2012, February 15). In Acronym Geek. Retrieved 10:49, February 15, 2012, from http://www.acronymgeek.com/LPEN |
| MLA | "LPEN." Acronym Geek. (2012). Acronym Geek. 15 Feb 2012 <http://www.acronymgeek.com/LPEN>. |
| MHRA | 'LPEN', Acronym Geek, 15 February 2012, <http://www.acronymgeek.com/LPEN> [accessed 15 February 2012] |
| Chicago | "LPEN", http://www.acronymgeek.com/LPEN (accessed February 15, 2012). |
| CBE/CSE | LPEN [Internet]. Acronym Geek; 2012 Feb 15 [cited 2012 Feb 15]. Available from: http://www.acronymgeek.com/LPEN. |
| Bluebook | LPEN, http://www.acronymgeek.com/LPEN (last visited February 15, 2012). |
| Bluebook: Harvard JOLT | See Acronym Geek, LPEN, http://www.acronymgeek.com/LPEN (optional description here) (as of Feb. 15, 2012, 10:49). |
| AMA | LPEN. Acronym Geek. February 15, 2012, 10:49. Available at: http://www.acronymgeek.com/LPEN. Accessed February 15, 2012, 10:49. |