Tadeusz Pankowski A High-Level Language for Specifying XML Data Transformations. 159-172 http://springerlink.metapress.com/openurl.asp?genre=article&issn=0302-9743&volume=3255&spage=159 2004 conf/adbis/2004 ADBIS db/conf/adbis/adbis2004.html#Pankowski04