| APA | 581. (2012, February 11). In Acronym Geek. Retrieved 22:52, February 11, 2012, from http://www.acronymgeek.com/581 |
| MLA | "581." Acronym Geek. (2012). Acronym Geek. 11 Feb 2012 <http://www.acronymgeek.com/581>. |
| MHRA | '581', Acronym Geek, 11 February 2012, <http://www.acronymgeek.com/581> [accessed 11 February 2012] |
| Chicago | "581", http://www.acronymgeek.com/581 (accessed February 11, 2012). |
| CBE/CSE | 581 [Internet]. Acronym Geek; 2012 Feb 11 [cited 2012 Feb 11]. Available from: http://www.acronymgeek.com/581. |
| Bluebook | 581, http://www.acronymgeek.com/581 (last visited February 11, 2012). |
| Bluebook: Harvard JOLT | See Acronym Geek, 581, http://www.acronymgeek.com/581 (optional description here) (as of Feb. 11, 2012, 22:52). |
| AMA | 581. Acronym Geek. February 11, 2012, 22:52. Available at: http://www.acronymgeek.com/581. Accessed February 11, 2012, 22:52. |