Young people's inventive activity in Bulgaria : a form of selfexpression in the technological and scientific field and a contribution to peace
Alexandrov, Ch.
Young people's inventive activity in Bulgaria : a form of selfexpression in the technological and scientific field and a contribution to peace
Bulgarien
Erfinder
Young people's inventive activity in Bulgaria : a form of selfexpression in the technological and scientific field and a contribution to peace
Bulgarien
Erfinder