Thorsten Schmitt Robert Hanek Michael Beetz Developing Comprehensive State Estimators for Robot Soccer. 397-409 http://springerlink.metapress.com/openurl.asp?genre=article&issn=0302-9743&volume=3020&spage=397 2003 conf/robocup/2003 RoboCup db/conf/robocup/robocup2003.html#SchmittHB03