| APA | 4WS. (2012, February 10). In Acronym Geek. Retrieved 11:18, February 10, 2012, from http://www.acronymgeek.com/4WS |
| MLA | "4WS." Acronym Geek. (2012). Acronym Geek. 10 Feb 2012 <http://www.acronymgeek.com/4WS>. |
| MHRA | '4WS', Acronym Geek, 10 February 2012, <http://www.acronymgeek.com/4WS> [accessed 10 February 2012] |
| Chicago | "4WS", http://www.acronymgeek.com/4WS (accessed February 10, 2012). |
| CBE/CSE | 4WS [Internet]. Acronym Geek; 2012 Feb 10 [cited 2012 Feb 10]. Available from: http://www.acronymgeek.com/4WS. |
| Bluebook | 4WS, http://www.acronymgeek.com/4WS (last visited February 10, 2012). |
| Bluebook: Harvard JOLT | See Acronym Geek, 4WS, http://www.acronymgeek.com/4WS (optional description here) (as of Feb. 10, 2012, 11:18). |
| AMA | 4WS. Acronym Geek. February 10, 2012, 11:18. Available at: http://www.acronymgeek.com/4WS. Accessed February 10, 2012, 11:18. |