Sanjay Jain The Intrinsic Complexity of Learning: A Survey. 17-37 2003 57 Fundam. Inform. 1 http://iospress.metapress.com/openurl.asp?genre=article&issn=0169-2968&volume=57&issue=1&spage=17 db/journals/fuin/fuin57.html#Jain03