Numerical Solution of Partial Differential Equations: Theory, Algorithms, and Their Applications [electronic resource] : In Honor of Professor Raytcho Lazarov's 40 Years of Research in Computational Methods and Applied Mathematics / edited by Oleg P. Iliev, Svetozar D. Margenov, Peter D Minev, Panayot S. Vassilevski, Ludmil T Zikatanov.