Troyan, Oksana     Analysis and development of latent elements as a methodto protect documents [Текст] / Oksana Troyan, Tanya Tomashchuk // Computer science and information technologies CSIT 2014 : proc. of the IX Intern. sci. and techn. conf., Nov. 18-22, 2014, Lviv, Ukraine / Min. of Education and Science of Ukraine, Lviv Politechniс Nat. Univ. — Lviv : Publ. Lviv Politechniс, 2014. — P. 91-92.