1. Infinitary logic and admissible sets;Barwise;J. Symbolic Logic,1969
2. Infinitary methods in the model theory of set theory;Barwise,1971
3. Uniform extension operators for models and their applications;Gaifmann,1965
4. Models of ZF set theory;Felgner,1970
5. The Boolean prime ideal theorem does not imply the axiom of choice;Halpern,1971