| Style | Reference Text |
|---|
| APA | 21C. (2009, January 5). In All Acronyms. Retrieved 18:04, January 5, 2009, from http://www.all-acronyms.com/21C |
| MLA | "21C." All Acronyms. 5 Jan 2009, 18:04. All Acronyms. 5 Jan 2009 <http://www.all-acronyms.com/21C>. |
| MHRA | '21C', All Acronyms, 5 January 2009, 18:04, <http://www.all-acronyms.com/21C> [accessed 5 January 2009] |
| Chicago | "21C," http://www.all-acronyms.com/21C (accessed January 5, 2009). |
| CBE/CSE | 21C [Internet]. All Acronyms; 2009 Jan 5, 18:04 [cited 2009 Jan 5]. Available from: http://www.all-acronyms.com/21C. |
| Bluebook | 21C, http://www.all-acronyms.com/21C (last visited January 5, 2009). |
| Bluebook: Harvard JOLT | See All Acronyms, 21C, http://www.all-acronyms.com/21C (optional description here) (as of Jan. 5, 2009, 18:04). |
| AMA | 21C. All Acronyms. January 5, 2009, 18:04. Available at: http://www.all-acronyms.com/21C. Accessed January 5, 2009. |
Second-in-Command