1. Department of Neurology, Medical University of Plovdiv, Plovdiv, Bulgaria
2. Department of Medical Biology, Medical University of Plovdiv, Plovdiv, Bulgaria
3. Department of Medical Informatics, Biostatistics and Electronic Education, Medical University of Plovdiv, Plovdiv, Bulgaria
4. Department of Molecular Biology, Immunology and Medical Genetics, Trakia University, Stara Zagora, Bulgaria