Charalampos Cornaros. Pell Equations and Weak Regularity Principles. In Arnold Beckmann, Costas Dimitracopoulos, Benedikt Löwe, editors, Logic and Theory of Algorithms, 4th Conference on Computability in Europe, CiE 2008, Athens, Greece, June 15-20, 2008, Proceedings. Volume 5028 of Lecture Notes in Computer Science, pages 129-138, Springer, 2008. [doi]