Andrzej Filinski Henning Korsholm Rohde A Denotational Account of Untyped Normalization by Evaluation. 167-181 http://springerlink.metapress.com/openurl.asp?genre=article&issn=0302-9743&volume=2987&spage=167 2004 conf/fossacs/2004 FoSSaCS db/conf/fossacs/fossacs2004.html#FilinskiR04