| APA | ZK. (2012, February 11). In Acronym Geek. Retrieved 21:53, February 11, 2012, from http://www.acronymgeek.com/ZK |
| MLA | "ZK." Acronym Geek. (2012). Acronym Geek. 11 Feb 2012 <http://www.acronymgeek.com/ZK>. |
| MHRA | 'ZK', Acronym Geek, 11 February 2012, <http://www.acronymgeek.com/ZK> [accessed 11 February 2012] |
| Chicago | "ZK", http://www.acronymgeek.com/ZK (accessed February 11, 2012). |
| CBE/CSE | ZK [Internet]. Acronym Geek; 2012 Feb 11 [cited 2012 Feb 11]. Available from: http://www.acronymgeek.com/ZK. |
| Bluebook | ZK, http://www.acronymgeek.com/ZK (last visited February 11, 2012). |
| Bluebook: Harvard JOLT | See Acronym Geek, ZK, http://www.acronymgeek.com/ZK (optional description here) (as of Feb. 11, 2012, 21:53). |
| AMA | ZK. Acronym Geek. February 11, 2012, 21:53. Available at: http://www.acronymgeek.com/ZK. Accessed February 11, 2012, 21:53. |