Alan L. Selman Samik Sengupta Polylogarithmic-Round Interactive Proofs for coNP Collapse the Exponential Hierarchy. 82-90 2004 conf/coco/2004 IEEE Conference on Computational Complexity http://csdl.computer.org/comp/proceedings/ccc/2004/2120/00/21200082abs.htm db/conf/coco/coco2004.html#SelmanS04