Strykhaliuk, B.     Applying the backup overlay concept to security purposes [Текст] / B. Strykhaliuk, B. Koval, Z. Kharkhalis // Advanced information and communication technologies-2015 : proc. of 1st Intern. conf., Oct. 29 - Nov. 1, 2015, Lviv, Ukraine / Lviv Polytechnic Nat. Univ. — Lviv, 2015. — P. 151-152.