Zhuravchak, L. M.     Consideration of the nonlinear behavior of environmental material and a three-dimensional internal heat sources in mathematical modeling of heat conduction [Текст] / L.M. Zhuravchak, O.S. Kruk // Mathematical Modeling and Computing / Lviv Polytechnic Nat. Univ. ; ed.-in-chief Yuriy Bobalo. — Lviv : Lviv Polytechnic Nat. Univ., 2014. — P. 107-113.