Analytic Sets Having Incomparable Kleene Degrees. - Galen Weitkamp (J. Symb. Log., 1982)

Iterating the Superjump Along Definable Prewellorderings. - Galen Weitkamp (Math. Log. Q., 1982)

High and Low Kleene Degrees of Coanalytic Sets. - Stephen G. Simpson; Galen Weitkamp (J. Symb. Log., 1983)

Effective topological spaces I: a definability theory. - Iraj Kalantari; Galen Weitkamp (Ann. Pure Appl. Log., 1985)

Effective topological spaces II: A hierarchy. - Iraj Kalantari; Galen Weitkamp (Ann. Pure Appl. Log., 1985)

On the Existence and Recursion Theoretic Properties of ∑. - Galen Weitkamp (Math. Log. Q., 1985)

Effective topological spaces III: Forcing and definability. - Iraj Kalantari; Galen Weitkamp (Ann. Pure Appl. Log., 1987)

The Sigma12 Theory of Axioms of Symmetry. - Galen Weitkamp (J. Symb. Log., 1989)