| APA | R2. (2012, February 14). In Acronym Geek. Retrieved 06:51, February 14, 2012, from http://www.acronymgeek.com/R2 |
| MLA | "R2." Acronym Geek. (2012). Acronym Geek. 14 Feb 2012 <http://www.acronymgeek.com/R2>. |
| MHRA | 'R2', Acronym Geek, 14 February 2012, <http://www.acronymgeek.com/R2> [accessed 14 February 2012] |
| Chicago | "R2", http://www.acronymgeek.com/R2 (accessed February 14, 2012). |
| CBE/CSE | R2 [Internet]. Acronym Geek; 2012 Feb 14 [cited 2012 Feb 14]. Available from: http://www.acronymgeek.com/R2. |
| Bluebook | R2, http://www.acronymgeek.com/R2 (last visited February 14, 2012). |
| Bluebook: Harvard JOLT | See Acronym Geek, R2, http://www.acronymgeek.com/R2 (optional description here) (as of Feb. 14, 2012, 06:51). |
| AMA | R2. Acronym Geek. February 14, 2012, 06:51. Available at: http://www.acronymgeek.com/R2. Accessed February 14, 2012, 06:51. |