Second VarSITI General Symposium (VarSITI-2017) was held with the financial support of the Russian Foundation for Basic Research, Project No. 17-05-20306.
Danov, Dimitar, <em>Space Research and Technology Institute, Bulgarian Academy of Sciences, 1113 Sofia, Acad. Gerogy Bonchev Str. Bl. 1, Bulgaria</em>, Bulgaria
