| APA | NPL. (2012, February 7). In Acronym Geek. Retrieved 22:44, February 7, 2012, from http://www.acronymgeek.com/NPL |
| MLA | "NPL." Acronym Geek. (2012). Acronym Geek. 7 Feb 2012 <http://www.acronymgeek.com/NPL>. |
| MHRA | 'NPL', Acronym Geek, 7 February 2012, <http://www.acronymgeek.com/NPL> [accessed 7 February 2012] |
| Chicago | "NPL", http://www.acronymgeek.com/NPL (accessed February 7, 2012). |
| CBE/CSE | NPL [Internet]. Acronym Geek; 2012 Feb 7 [cited 2012 Feb 7]. Available from: http://www.acronymgeek.com/NPL. |
| Bluebook | NPL, http://www.acronymgeek.com/NPL (last visited February 7, 2012). |
| Bluebook: Harvard JOLT | See Acronym Geek, NPL, http://www.acronymgeek.com/NPL (optional description here) (as of Feb. 7, 2012, 22:44). |
| AMA | NPL. Acronym Geek. February 7, 2012, 22:44. Available at: http://www.acronymgeek.com/NPL. Accessed February 7, 2012, 22:44. |