| APA | MRK. (2012, February 15). In Acronym Geek. Retrieved 03:30, February 15, 2012, from http://www.acronymgeek.com/MRK |
| MLA | "MRK." Acronym Geek. (2012). Acronym Geek. 15 Feb 2012 <http://www.acronymgeek.com/MRK>. |
| MHRA | 'MRK', Acronym Geek, 15 February 2012, <http://www.acronymgeek.com/MRK> [accessed 15 February 2012] |
| Chicago | "MRK", http://www.acronymgeek.com/MRK (accessed February 15, 2012). |
| CBE/CSE | MRK [Internet]. Acronym Geek; 2012 Feb 15 [cited 2012 Feb 15]. Available from: http://www.acronymgeek.com/MRK. |
| Bluebook | MRK, http://www.acronymgeek.com/MRK (last visited February 15, 2012). |
| Bluebook: Harvard JOLT | See Acronym Geek, MRK, http://www.acronymgeek.com/MRK (optional description here) (as of Feb. 15, 2012, 03:30). |
| AMA | MRK. Acronym Geek. February 15, 2012, 03:30. Available at: http://www.acronymgeek.com/MRK. Accessed February 15, 2012, 03:30. |