Secular changes in the quiescence of WZ Sagittae: the development of a cavity in the inner disk E. Kuulkers, A. A. Henden, R. K. Honeycutt, W. Skidmore, E. O. Waagen and G. A. Wynn A&A, 528 (2011) A152 Published online: 18 March 2011 DOI: 10.1051/0004-6361/201014141