| APA | OS. (2012, February 14). In Acronym Geek. Retrieved 06:09, February 14, 2012, from http://www.acronymgeek.com/OS |
| MLA | "OS." Acronym Geek. (2012). Acronym Geek. 14 Feb 2012 <http://www.acronymgeek.com/OS>. |
| MHRA | 'OS', Acronym Geek, 14 February 2012, <http://www.acronymgeek.com/OS> [accessed 14 February 2012] |
| Chicago | "OS", http://www.acronymgeek.com/OS (accessed February 14, 2012). |
| CBE/CSE | OS [Internet]. Acronym Geek; 2012 Feb 14 [cited 2012 Feb 14]. Available from: http://www.acronymgeek.com/OS. |
| Bluebook | OS, http://www.acronymgeek.com/OS (last visited February 14, 2012). |
| Bluebook: Harvard JOLT | See Acronym Geek, OS, http://www.acronymgeek.com/OS (optional description here) (as of Feb. 14, 2012, 06:09). |
| AMA | OS. Acronym Geek. February 14, 2012, 06:09. Available at: http://www.acronymgeek.com/OS. Accessed February 14, 2012, 06:09. |