1. Uniform extension operators for models and their applications;Gaifman,1967
2. On local arithmetical functions, and their applications for constructiong types of Peano's arithmetic;Gaifman,1970
3. Models and types of Peano's arithmetic;Gaifman;Ann. Math. Logic,1976
4. Lattice Theory: First Concepts and Distributive Lattices;Grätzer,1971
5. Hanf numbers for omitting types over particular theories;Knight;J. Symbolic Logic,1976