André Bergholz Boris Chidlovskii Using Query Probing to Identify Query Language Features on the Web. 21-30 http://springerlink.metapress.com/openurl.asp?genre=article&issn=0302-9743&volume=2924&spage=21 2003 conf/sigir/2003dmir Distributed Multimedia Information Retrieval db/conf/sigir/sigir2003dmir.html#BergholzC03