Nonstandard Logic. - James R. Geiser (J. Symb. Log., 1968)

A Formalization of Essenin-Volpin's Proof Theoretical Studies by Means of Nonstandard Analysis. - James R. Geiser (J. Symb. Log., 1974)

Commenting Proofs. - James R. Geiser (IJCAI, 1975)

An Efficient Decision Procedure for the Theory of Rational Order. - Jeanne Ferrante; James R. Geiser (Theor. Comput. Sci., 1977)