Authors
Dragomir Marchev
University of Shumen, Faculty of Natural Sciences, Department of Physics and Astronomy, Shumen, Bulgaria
Georgi Dimitrov
University of Shumen, Faculty of Mathematics and Informatics, Department of Computer Informatics, Shumen, Bulgaria
Nataliya Pavlova
University of Shumen, Faculty of Mathematics and Informatics, Department of Computer Informatics, Shumen, Bulgaria
Doroteq Vasileva
University of Shumen, Faculty of Natural Sciences, Department of Physics and Astronomy, Shumen, Bulgaria
Borislav Borisov
University of Shumen, Faculty of Natural Sciences, Department of Physics and Astronomy, Shumen, Bulgaria
Teodora Atanasova
University of Shumen, Faculty of Natural Sciences, Department of Physics and Astronomy, Shumen, Bulgaria
Vladislav Marchev
Institute of Astronomy and National Astronomical Observatory, Bulgarian Academy of Sciences, Sofia, Bulgaria