2Peter de Groot, Xavier Colonna de Lega. Valve cone measurement using white light interference microscopy in a spherical measurement geometry [ J]. Society of Photo - Optical Instrumentation Engineers, 2003, 42(5) : 1232-1237.
3Ildeu Ldcio Siqueira, Helder Barbieri Lacerda, Paulo Srrgio Martins et al. Boring of the admission valve seats of the internal combustion en gines [ R ]. 20th International Congress of Mechanical Engineering November 15 - 20, 2009, Gramado, RS, Brazil.
