1. Institute of Robotics, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria
2. Department of Logopedics, South-West University “Neofit Rilski”, 2700 Blagoevgrad, Bulgaria
3. Faculty of Information Sciences, University of Library Studies and Information Technologies, 1784 Sofia, Bulgaria
4. Department of Medical-Social Sciences, South-West University “Neofit Rilski”, 2700 Blagoevgrad, Bulgaria