Abstract
Let L>=K be fields of characteristic p /= 0 such that Lpe <= K for some positive integer e. Let M be an inbetween field of K and L and f the canonical K-homo-morphism of the tensor product L ⊗ M over K onto the field composite LM = L. The purpose of this thesis is to study the existence of 1 ⊗ M-coefficient fields of L ⊗ M.