Adam Bakewell Detlef Plump Colin Runciman Specifying Pointer Structures by Graph Reduction. 30-44 http://springerlink.metapress.com/openurl.asp?genre=article&issn=0302-9743&volume=3062&spage=30 2003 conf/agtive/2003 AGTIVE db/conf/agtive/agtive2003.html#BakewellPR03