Feferman, Solomon, Formal Consistency Proofs and Interpretability of Theories Feferman, Solomon, Infinitary Properties, Local Functors, and Systems of Ordinal Functions Feferman, Solomon, Infinity in Mathematics: Is Cantor Necessary? Feferman, Solomon, Investigative Logic for Theories of Partial Functions and Relations, I. Feferman, Solomon, Mathematics as Objective Subjectivity Feferman, Solomon, Persistent and Invariant Formulas for Outer Extensions Feferman, Solomon, Sentences of Arithmetic which Formally Express Consistency Feferman, Solomon, Some Formal Systems for the Unlimited Theory of Structures and Categories Feferman, Solomon, The Logic of Mathematical Discovery vs. The Logical Structure of Mathematics Feferman, Solomon, Working Foundations