| APA | S2. (2012, February 10). In Acronym Geek. Retrieved 10:44, February 10, 2012, from http://www.acronymgeek.com/S2 |
| MLA | "S2." Acronym Geek. (2012). Acronym Geek. 10 Feb 2012 <http://www.acronymgeek.com/S2>. |
| MHRA | 'S2', Acronym Geek, 10 February 2012, <http://www.acronymgeek.com/S2> [accessed 10 February 2012] |
| Chicago | "S2", http://www.acronymgeek.com/S2 (accessed February 10, 2012). |
| CBE/CSE | S2 [Internet]. Acronym Geek; 2012 Feb 10 [cited 2012 Feb 10]. Available from: http://www.acronymgeek.com/S2. |
| Bluebook | S2, http://www.acronymgeek.com/S2 (last visited February 10, 2012). |
| Bluebook: Harvard JOLT | See Acronym Geek, S2, http://www.acronymgeek.com/S2 (optional description here) (as of Feb. 10, 2012, 10:44). |
| AMA | S2. Acronym Geek. February 10, 2012, 10:44. Available at: http://www.acronymgeek.com/S2. Accessed February 10, 2012, 10:44. |