Authors
I. P. Bangov
“Konstantin Preslavsky” University of Shumen, Faculty of Natural Sciences, Department of Chemistry, Shumen, Bulgaria
M. Moskovkina
“Konstantin Preslavsky” University of Shumen, Faculty of Natural Sciences, Department of Chemistry, Shumen, Bulgaria
B. P. Stojanov
“Konstantin Preslavsky” University of Shumen, Faculty of Natural Sciences, Department of Chemistry, Shumen, Bulgaria