Claus-Peter Wirth. Full First-Order Sequent and Tableau Calculi with Preservation of Solutions and the Liberalized delta-Rule but without Skolemization. In Ricardo Caferra, Gernot Salzer, editors, Automated Deduction in Classical and Non-Classical Logics, Selected Papers. Volume 1761 of Lecture Notes in Computer Science, pages 282-297, Springer, 1998. [doi]
Abstract is missing.