Willi Meier Enes Pasalic Claude Carlet Algebraic Attacks and Decomposition of Boolean Functions. 474-491 http://springerlink.metapress.com/openurl.asp?genre=article&issn=0302-9743&volume=3027&spage=474 2004 conf/eurocrypt/2004 EUROCRYPT db/conf/eurocrypt/eurocrypt2004.html#MeierPC04