1. Transilvania University of Brasov,Department of Electrical Engineering and Applied Physics,Brasov,Romania,500036
2. Technological University of Havana,Department of Electrical Engineering,Havana,Cuba,19390
3. Granma Naval Academic,Department of Electrical Engineering,Havana,Cuba,16009
4. Steel Company "José Martí,Department of Electrical Engineering,Havana,Cuba,14000