| APA | 990. (2012, February 11). In Acronym Geek. Retrieved 22:39, February 11, 2012, from http://www.acronymgeek.com/990 |
| MLA | "990." Acronym Geek. (2012). Acronym Geek. 11 Feb 2012 <http://www.acronymgeek.com/990>. |
| MHRA | '990', Acronym Geek, 11 February 2012, <http://www.acronymgeek.com/990> [accessed 11 February 2012] |
| Chicago | "990", http://www.acronymgeek.com/990 (accessed February 11, 2012). |
| CBE/CSE | 990 [Internet]. Acronym Geek; 2012 Feb 11 [cited 2012 Feb 11]. Available from: http://www.acronymgeek.com/990. |
| Bluebook | 990, http://www.acronymgeek.com/990 (last visited February 11, 2012). |
| Bluebook: Harvard JOLT | See Acronym Geek, 990, http://www.acronymgeek.com/990 (optional description here) (as of Feb. 11, 2012, 22:39). |
| AMA | 990. Acronym Geek. February 11, 2012, 22:39. Available at: http://www.acronymgeek.com/990. Accessed February 11, 2012, 22:39. |