Holger Spakowski, Jörg Vogel. The Operators minCh and maxCh on the Polynomial Hierarchy. In Gabriel Ciobanu, Gheorghe Paun, editors, Fundamentals of Computation Theory, 12th International Symposium, FCT 99, Iasi, Romania, August 30 - September 3, 1999, Proceedings. Volume 1684 of Lecture Notes in Computer Science, pages 524-535, Springer, 1999. [doi]
Abstract is missing.