1. Department of Business Administration, School of Business, Economics and Social Sciences, University of West Attica, 250 Thivon & P. Ralli str, 12244 Egaleo, Greece
2. Electric Power Division, Photometry Laboratory, School of Electrical and Computer Engineering, National Technical University of Athens, 15780 Athens
3. 2nd Elementary School of Skydra, Fintia 1, Skydra, 58500, Greece