Shchur, Ihor     Computer simulation of an autonomous contra-rotating wind turbine taking into account parameter differences and wind rotor work conditions [Текст] / Ihor Shchur, Andrii Kovalchuk // Computational problems of electrical engineering / Lviv Polytechnic nat. univ. ; ed.-in-chief Yuriy Bobalo. — Lviv : lviv Polytechnic nat. univ., 2012. — P. 69-74.