Алексеев, В. А., Ю. А. Синица, and Д. Ю. Горелов. “Modified Digraphs Method in the Problem of Authenticating Users Using Keystroke Dynamics”. Ukrainian Information Security Research Journal, vol. 18, no. 4, Dec. 2016, pp. 252-61, doi:10.18372/2410-7840.18.11084.