Vachkova, Ekaterina
Bosnakovski, D.
Yonkova, P.
Grigorova, N.
Ivanova, Zh.
Todorov, P.
Penchev, G.
Milanova, A.
Simeonova, G.
Stanilova, S.
Georgiev, I. Penchev
Funding for this research was provided by:
Trakia University-FVM (Project 4/13)