1. Axiomatic foundations for nonstandard analysis;Hrbacek;Fund. Math.,1978
2. Internal set theory: A new approach to nonstandard analysis;Nelson;Bull. Amer. Math. Soc.,1977
3. An axiom system for nonstandard set theory;Kawai;Rep. Fac. Sci., Kagoshima Univ. (Math. Phys. & Chem.),1979
4. Axiom systems of nonstandard set theory;Kawai,1981