| APA | FS-21. (2012, February 11). In Acronym Geek. Retrieved 17:26, February 11, 2012, from http://www.acronymgeek.com/FS-21 |
| MLA | "FS-21." Acronym Geek. (2012). Acronym Geek. 11 Feb 2012 <http://www.acronymgeek.com/FS-21>. |
| MHRA | 'FS-21', Acronym Geek, 11 February 2012, <http://www.acronymgeek.com/FS-21> [accessed 11 February 2012] |
| Chicago | "FS-21", http://www.acronymgeek.com/FS-21 (accessed February 11, 2012). |
| CBE/CSE | FS-21 [Internet]. Acronym Geek; 2012 Feb 11 [cited 2012 Feb 11]. Available from: http://www.acronymgeek.com/FS-21. |
| Bluebook | FS-21, http://www.acronymgeek.com/FS-21 (last visited February 11, 2012). |
| Bluebook: Harvard JOLT | See Acronym Geek, FS-21, http://www.acronymgeek.com/FS-21 (optional description here) (as of Feb. 11, 2012, 17:26). |
| AMA | FS-21. Acronym Geek. February 11, 2012, 17:26. Available at: http://www.acronymgeek.com/FS-21. Accessed February 11, 2012, 17:26. |