  The processes e+e- -> t tbar/b bbar + Higgs allow to measure the Yukawa
couplings between Higgs bosons and heavy quarks in supersymmetric theories. The
complete set of next-to-leading order SUSY-QCD corrections to the cross
sections of these processes have been determined in the minimal supersymmetric
extension of the Standard Model. They turn out to be O(10-20%) and thus
important for future linear e+e- colliders.
