David Guijarro Víctor Lavín Vijay Raghavan Exact Learning when Irrelevant Variables Abound. 91-100 http://link.springer.de/link/service/series/0558/bibs/1572/15720091.htm 1999 conf/eurocolt/1999 EuroCOLT db/conf/eurocolt/eurocolt1999.html#GuijarroLR99