| APA | SO2. (2012, February 11). In Acronym Geek. Retrieved 22:23, February 11, 2012, from http://www.acronymgeek.com/SO2 |
| MLA | "SO2." Acronym Geek. (2012). Acronym Geek. 11 Feb 2012 <http://www.acronymgeek.com/SO2>. |
| MHRA | 'SO2', Acronym Geek, 11 February 2012, <http://www.acronymgeek.com/SO2> [accessed 11 February 2012] |
| Chicago | "SO2", http://www.acronymgeek.com/SO2 (accessed February 11, 2012). |
| CBE/CSE | SO2 [Internet]. Acronym Geek; 2012 Feb 11 [cited 2012 Feb 11]. Available from: http://www.acronymgeek.com/SO2. |
| Bluebook | SO2, http://www.acronymgeek.com/SO2 (last visited February 11, 2012). |
| Bluebook: Harvard JOLT | See Acronym Geek, SO2, http://www.acronymgeek.com/SO2 (optional description here) (as of Feb. 11, 2012, 22:23). |
| AMA | SO2. Acronym Geek. February 11, 2012, 22:23. Available at: http://www.acronymgeek.com/SO2. Accessed February 11, 2012, 22:23. |