| APA | HDYS. (2012, February 16). In Acronym Geek. Retrieved 11:37, February 16, 2012, from http://www.acronymgeek.com/HDYS |
| MLA | "HDYS." Acronym Geek. (2012). Acronym Geek. 16 Feb 2012 <http://www.acronymgeek.com/HDYS>. |
| MHRA | 'HDYS', Acronym Geek, 16 February 2012, <http://www.acronymgeek.com/HDYS> [accessed 16 February 2012] |
| Chicago | "HDYS", http://www.acronymgeek.com/HDYS (accessed February 16, 2012). |
| CBE/CSE | HDYS [Internet]. Acronym Geek; 2012 Feb 16 [cited 2012 Feb 16]. Available from: http://www.acronymgeek.com/HDYS. |
| Bluebook | HDYS, http://www.acronymgeek.com/HDYS (last visited February 16, 2012). |
| Bluebook: Harvard JOLT | See Acronym Geek, HDYS, http://www.acronymgeek.com/HDYS (optional description here) (as of Feb. 16, 2012, 11:37). |
| AMA | HDYS. Acronym Geek. February 16, 2012, 11:37. Available at: http://www.acronymgeek.com/HDYS. Accessed February 16, 2012, 11:37. |