Czaplewski, Bartosz, Mariusz Dzwonkowski, and Roman Rykaczewski. “Digital Fingerprinting Based on Quaternion Encryption Scheme for Gray-Tone Images”. Journal of Telecommunications and Information Technology 56, no. 2 (June 30, 2014): 3–11. Accessed May 23, 2026. https://www.jtit.pl/jtit/article/view/1016.