| Style | Reference Text |
|---|
| APA | 21C. (2009, November 23). In All Acronyms. Retrieved 23:56, November 23, 2009, from http://www.all-acronyms.com/21C |
| MLA | "21C." All Acronyms. 23 Nov 2009, 23:56. All Acronyms. 23 Nov 2009 <http://www.all-acronyms.com/21C>. |
| MHRA | '21C', All Acronyms, 23 November 2009, 23:56, <http://www.all-acronyms.com/21C> [accessed 23 November 2009] |
| Chicago | "21C," http://www.all-acronyms.com/21C (accessed November 23, 2009). |
| CBE/CSE | 21C [Internet]. All Acronyms; 2009 Nov 23, 23:56 [cited 2009 Nov 23]. Available from: http://www.all-acronyms.com/21C. |
| Bluebook | 21C, http://www.all-acronyms.com/21C (last visited November 23, 2009). |
| Bluebook: Harvard JOLT | See All Acronyms, 21C, http://www.all-acronyms.com/21C (optional description here) (as of Nov. 23, 2009, 23:56). |
| AMA | 21C. All Acronyms. November 23, 2009, 23:56. Available at: http://www.all-acronyms.com/21C. Accessed November 23, 2009. |
Second-in-Command