| APA | OBS. (2012, February 13). In Acronym Geek. Retrieved 21:34, February 13, 2012, from http://www.acronymgeek.com/OBS |
| MLA | "OBS." Acronym Geek. (2012). Acronym Geek. 13 Feb 2012 <http://www.acronymgeek.com/OBS>. |
| MHRA | 'OBS', Acronym Geek, 13 February 2012, <http://www.acronymgeek.com/OBS> [accessed 13 February 2012] |
| Chicago | "OBS", http://www.acronymgeek.com/OBS (accessed February 13, 2012). |
| CBE/CSE | OBS [Internet]. Acronym Geek; 2012 Feb 13 [cited 2012 Feb 13]. Available from: http://www.acronymgeek.com/OBS. |
| Bluebook | OBS, http://www.acronymgeek.com/OBS (last visited February 13, 2012). |
| Bluebook: Harvard JOLT | See Acronym Geek, OBS, http://www.acronymgeek.com/OBS (optional description here) (as of Feb. 13, 2012, 21:34). |
| AMA | OBS. Acronym Geek. February 13, 2012, 21:34. Available at: http://www.acronymgeek.com/OBS. Accessed February 13, 2012, 21:34. |