1. Peter Aczel and Sol Feferman. Consistency of the unrestricted abstraction principle using an intensional equivalence operator. In J.P. Seldin and J.R. Hindley, editors, To H. B. Curry: Essays on Combinatory Logic, Lambda Calculus and Formalism, pages 67–98. Academic Press, New York, 1980.
2. Aczel et al.,1991] P. Aczel, P. Carlisle, and N. Mendier. Two frameworks of theories and their implementation in isabelle. In G. M. Plotkin et al., editors, Logical Frameworks,pages 5–39. Cambridge University Press, Cambridge, 1991.
3. P. Aczel. The strength of Martin-Löf’s intuitionistic type theory with one universe. In S. Mietissen and J. Vaänänen, editors, Proceedings of the Symposiums in Mathematical Logic in Oulu 1974 and Helsinki 1975, pages 1–32. Report no. 2, Dept.of Philosophy, University of Helsinki, 1977.
4. Peter Aczel. An introduction to inductive definitions. In Jon Barwise, editor, Handbook of Mathematical Logic, pages 739–782. North Holland, Amsterdam, 1977.
5. Aczel, 1980] Peter Aczel. Frege structures and the notions of proposition, truth and set. In Jon Barwise et al., editors, The Kleene Symposium,pages 31–59. North Holland, Amsterdam, 1980.