Authors
Nevena Ilieva
Institute of Information and Communication Technologies, Bulgarian Academy of Sciences, 1113, Sofia, Bulgaria
Elena Lilkova
Institute of Information and Communication Technologies, Bulgarian Academy of Sciences, 1113, Sofia, Bulgaria
Leandar Litov
Sofia University “St. Kl. Ohridski”, Physics Faculty, 1000, Sofia, Bulgaria
Borislav Pavlov
Sofia University “St. Kl. Ohridski”, Physics Faculty, 1000, Sofia, Bulgaria
Peicho Petkov
Sofia University “St. Kl. Ohridski”, Physics Faculty, 1000, Sofia, Bulgaria
