| APA | HRYO. (2012, February 17). In Acronym Geek. Retrieved 07:36, February 17, 2012, from http://www.acronymgeek.com/HRYO |
| MLA | "HRYO." Acronym Geek. (2012). Acronym Geek. 17 Feb 2012 <http://www.acronymgeek.com/HRYO>. |
| MHRA | 'HRYO', Acronym Geek, 17 February 2012, <http://www.acronymgeek.com/HRYO> [accessed 17 February 2012] |
| Chicago | "HRYO", http://www.acronymgeek.com/HRYO (accessed February 17, 2012). |
| CBE/CSE | HRYO [Internet]. Acronym Geek; 2012 Feb 17 [cited 2012 Feb 17]. Available from: http://www.acronymgeek.com/HRYO. |
| Bluebook | HRYO, http://www.acronymgeek.com/HRYO (last visited February 17, 2012). |
| Bluebook: Harvard JOLT | See Acronym Geek, HRYO, http://www.acronymgeek.com/HRYO (optional description here) (as of Feb. 17, 2012, 07:36). |
| AMA | HRYO. Acronym Geek. February 17, 2012, 07:36. Available at: http://www.acronymgeek.com/HRYO. Accessed February 17, 2012, 07:36. |