| APA | 281. (2012, February 11). In Acronym Geek. Retrieved 23:12, February 11, 2012, from http://www.acronymgeek.com/281 |
| MLA | "281." Acronym Geek. (2012). Acronym Geek. 11 Feb 2012 <http://www.acronymgeek.com/281>. |
| MHRA | '281', Acronym Geek, 11 February 2012, <http://www.acronymgeek.com/281> [accessed 11 February 2012] |
| Chicago | "281", http://www.acronymgeek.com/281 (accessed February 11, 2012). |
| CBE/CSE | 281 [Internet]. Acronym Geek; 2012 Feb 11 [cited 2012 Feb 11]. Available from: http://www.acronymgeek.com/281. |
| Bluebook | 281, http://www.acronymgeek.com/281 (last visited February 11, 2012). |
| Bluebook: Harvard JOLT | See Acronym Geek, 281, http://www.acronymgeek.com/281 (optional description here) (as of Feb. 11, 2012, 23:12). |
| AMA | 281. Acronym Geek. February 11, 2012, 23:12. Available at: http://www.acronymgeek.com/281. Accessed February 11, 2012, 23:12. |