1. University of Prishtina, Department of Physics, Eqrem Çabej Str. 51, 10000 Prishtina, Kosovo
2. Polytechnic University of Tirana, Department of Physical Engineering, Mother Theresa Square No. 4, 1000 Tirana, Albania
3. State University of Tetovo, Faculty of Natural Sciences and Mathematics, Department of Physics, Ilinden Str., 1200 Tetovo, North Macedonia
4. University ``Kadri Zeka'', Faculty of Education, Zija Shemsiu Str. 03, 60000 Gjilan, Kosovo