1. Department of Analytical Chemistry and Computer Chemistry, Faculty of Chemistry, University of Plovdiv, “Tzar Asen” Str. 24, 4000 Plovdiv, Bulgaria
2. Department of Chemistry and Phytopharmacy, Faculty of Plant Protection and Agroecology, Agricultural University-Plovdiv, 4000 Plovdiv, Bulgaria
3. Department of General and Inorganic Chemistry with Methodology of Chemistry Education, Faculty of Chemistry, University of Plovdiv, “Tzar Assen” Str. 24, 4000 Plovdiv, Bulgaria
4. Department of Chemical, Food and Biotechnologies, “Angel Kanchev” University of Ruse, Razgrad Branch, 7200 Razgrad, Bulgaria