1. Iv.Javakhishvili Tbilisi State University, FENS, Tbilisi, Georgia
2. Muskhelishvili Institute of Computational Mathematics, Georgian Technical University, Tbilisi, Georgia
3. Department of Applied Physics II, Polytechnic School, Malaga University, Málaga, Spain
4. Department of Didactic of Mathematics, Education Faculty, Malaga University, Málaga, Spain