| APA | HL. (2012, February 4). In Acronym Geek. Retrieved 11:37, February 4, 2012, from http://www.acronymgeek.com/HL |
| MLA | "HL." Acronym Geek. (2012). Acronym Geek. 4 Feb 2012 <http://www.acronymgeek.com/HL>. |
| MHRA | 'HL', Acronym Geek, 4 February 2012, <http://www.acronymgeek.com/HL> [accessed 4 February 2012] |
| Chicago | "HL", http://www.acronymgeek.com/HL (accessed February 4, 2012). |
| CBE/CSE | HL [Internet]. Acronym Geek; 2012 Feb 4 [cited 2012 Feb 4]. Available from: http://www.acronymgeek.com/HL. |
| Bluebook | HL, http://www.acronymgeek.com/HL (last visited February 4, 2012). |
| Bluebook: Harvard JOLT | See Acronym Geek, HL, http://www.acronymgeek.com/HL (optional description here) (as of Feb. 4, 2012, 11:37). |
| AMA | HL. Acronym Geek. February 4, 2012, 11:37. Available at: http://www.acronymgeek.com/HL. Accessed February 4, 2012, 11:37. |