| Style | Reference Text |
|---|
| APA | 21C. (2013, May 23). In All Acronyms. Retrieved 06:44, May 23, 2013, from http://www.all-acronyms.com/21C |
| MLA | "21C." All Acronyms. 23 May 2013, 06:44. All Acronyms. 23 May 2013 <http://www.all-acronyms.com/21C>. |
| MHRA | '21C', All Acronyms, 23 May 2013, 06:44, <http://www.all-acronyms.com/21C> [accessed 23 May 2013] |
| Chicago | "21C," http://www.all-acronyms.com/21C (accessed May 23, 2013). |
| CBE/CSE | 21C [Internet]. All Acronyms; 2013 May 23, 06:44 [cited 2013 May 23]. Available from: http://www.all-acronyms.com/21C. |
| Bluebook | 21C, http://www.all-acronyms.com/21C (last visited May 23, 2013). |
| Bluebook: Harvard JOLT | See All Acronyms, 21C, http://www.all-acronyms.com/21C (optional description here) (as of May. 23, 2013, 06:44). |
| AMA | 21C. All Acronyms. May 23, 2013, 06:44. Available at: http://www.all-acronyms.com/21C. Accessed May 23, 2013. |
Second-in-Command