S. Feferman and W. Sieg Inductive definitions and subsystems of analysis. Iterated inductive definitions and subsystems of analysis: recent proof-theoretical studies, by Wilfried Buchholz, Solomon Feferman, Wolfram Pohlers, and Wilfried Sieg. Lecture notes in mathematics, vol. 897, Springer-Verlag, Berlin, Heidelberg, and New York, 1981, pp. 16–77. - Solomon Feferman and Wilfried Sieg. Proof theoretic equivalences between classical and constructive theories for analysis. Iterated inductive definitions and subsystems of analysis: recent proof-theoretical studies, by Wilfried Buchholz, Solomon Feferman, Wolfram Pohlers, and Wilfried Sieg. Lecture notes in mathematics, vol. 897, Springer-Verlag, Berlin, Heidelberg, and New York, 1981, pp. 78–142. - Solomon Feferman. Iterated inductive fixed-point theories: application to Hancock's conjecture. Patras logic symposion, Proceedings of the logic symposion held at Patras, Greece, August 18–22, 1980, edited by George Metakides, Studies in logic and the foundations of mathematics, vol. 109, NorthHolland Publishing Company, Amsterdam, New York, and Oxford, 1982, pp. 171–196. - Solomon Feferman. Monotone inductive definitions. The L. E. J. Brouwer centenary symposium, Proceedings of the conference held in Noordwijkerhout, 8–13 June, 1981, edited by A. S. Troelstra and D. van Dalen, Studies in logic and the foundations of mathematics, vol. 110, North-Holland Publishing Company, Amsterdam, New York, and Oxford, 1982, pp. 77–89. - S. Feferman and G. Jäger. Choice principles, the bar rule and autonomously iterated comprehension schemes in analysis. The journal of symbolic logic, vol. 48 (1983), pp. 63–70.