Distributed Concurrency Control in Database Systems. - Rudolf Bayer; Klaus Elhardt; Hans Heller; Angelika Reiser (VLDB, 1980)

Parallelism and Recovery in Database Systems. - Rudolf Bayer; Hans Heller; Angelika Reiser (ACM Trans. Database Syst., 1980)

Relativized polynomial hierarchies extending two levels. - Hans Heller (1981)

Relativized Polynomial Hierarchies Extending Two Levels. - Hans Heller (Math. Syst. Theory, 1984)

On Relativized Polynomial and Exponential Computations. - Hans Heller (SIAM J. Comput., 1984)

A Decisive Characterization of BPP - Stathis Zachos; Hans Heller (Inf. Control., 1986)

On Relativized Exponential and Probabilistic Complexity Classes - Hans Heller (Inf. Control., 1986)