| APA | 4NF. (2012, February 12). In Acronym Geek. Retrieved 07:03, February 12, 2012, from http://www.acronymgeek.com/4NF |
| MLA | "4NF." Acronym Geek. (2012). Acronym Geek. 12 Feb 2012 <http://www.acronymgeek.com/4NF>. |
| MHRA | '4NF', Acronym Geek, 12 February 2012, <http://www.acronymgeek.com/4NF> [accessed 12 February 2012] |
| Chicago | "4NF", http://www.acronymgeek.com/4NF (accessed February 12, 2012). |
| CBE/CSE | 4NF [Internet]. Acronym Geek; 2012 Feb 12 [cited 2012 Feb 12]. Available from: http://www.acronymgeek.com/4NF. |
| Bluebook | 4NF, http://www.acronymgeek.com/4NF (last visited February 12, 2012). |
| Bluebook: Harvard JOLT | See Acronym Geek, 4NF, http://www.acronymgeek.com/4NF (optional description here) (as of Feb. 12, 2012, 07:03). |
| AMA | 4NF. Acronym Geek. February 12, 2012, 07:03. Available at: http://www.acronymgeek.com/4NF. Accessed February 12, 2012, 07:03. |