en Magaud, Nicolas; Bertot, Yves (), „Changing data structures in type theory: a study of natural numbers”, Types for proofs and programs (Durham, 2000), Lecture Notes in Comput. Sci., 2277, Springer, Berlin, pp. 181–196, doi:10.1007/3-540-45842-5_12, ISBN978-3-540-43287-6, MR2044538
en Magaud, Nicolas; Bertot, Yves (), „Changing data structures in type theory: a study of natural numbers”, Types for proofs and programs (Durham, 2000), Lecture Notes in Comput. Sci., 2277, Springer, Berlin, pp. 181–196, doi:10.1007/3-540-45842-5_12, ISBN978-3-540-43287-6, MR2044538
en Jansen, Jan Martin (), „Programming in the λ-calculus: from Church to Scott and back”, The Beauty of Functional Code: Essays Dedicated to Rinus Plasmeijer on the Occasion of His 61st Birthday, Lecture Notes in Computer Science, 8106, Springer-Verlag, pp. 168–180, doi:10.1007/978-3-642-40355-2_12, ISBN978-3-642-40354-5