Nevin Lianwen Zhang Weihong Zhang Space-Progressive Value Iteration: An Anytime Algorithm for a Class of POMDPs. 72-83 2001 conf/ecsqaru/2001 ECSQARU http://springerlink.metapress.com/openurl.asp?genre=article&issn=0302-9743&volume=2143&spage=0072 db/conf/ecsqaru/ecsqaru2001.html#ZhangZ01