A. H. Nayfeh,J. E. Kaiser,International symposium on nonlinear acoustics abstracts.International symposium on nonlinear acoustics abstracts ( 7th : 1976 ).s. n. ],[1976].
W. A. Kaiser,W. E. Proebster,European Conference on Electronics- EUROCON`80.European Conference on Electronics- EUROCON`80 (4th : 1980 : Stuttgart):Form electronics to microelectronics.North-Holland,1980.