Grzegorz Bancerek Josef Urban Integrated Semantic Browsing of the Mizar Mathematical Library for Authoring Mizar Articles. 44-57 http://springerlink.metapress.com/openurl.asp?genre=article&issn=0302-9743&volume=3119&spage=44 2004 conf/mkm/2004 MKM db/conf/mkm/mkm2004.html#BancerekU04