Recursion theoretic operators and morphisms on numbered sets Henk Barendregt, Giuseppe Longo (1983) Fundamenta Mathematicae
Reducibilities of sets based on constructive functions of a real variable Osvald Demuth (1988) Commentationes Mathematicae Universitatis Carolinae
Reducibilities on tally and sparse sets Shouwen Tang, Ronald V. Book (1991) RAIRO - Theoretical Informatics and Applications - Informatique Théorique et Applications
Remarks on 1-genericity, semigenericity and related concepts Osvald Demuth, Antonín Kučera (1987) Commentationes Mathematicae Universitatis Carolinae
Remarks on the structure of tt-degrees based on constructive measure theory Osvald Demuth (1988) Commentationes Mathematicae Universitatis Carolinae