Some applications of the notions of forcing and generic sets S. Feferman — 1964 Fundamenta Mathematicae
1 - Consistency and Faithful Interpretations. G. Kreisel; S. Feferman Archiv für mathematische Logik und Grundlagenforschung
Representability of recursively enumerable sets in formal theories. A. Ehrenfeucht; S. Feferman Archiv für mathematische Logik und Grundlagenforschung
The first order properties of products of algebraic systems S. Feferman; R. Vaught — 1959 Fundamenta Mathematicae