(4) Zellner, J. W. and Weir, D. H. SAE Paper, No. 790260 (1979) ; Aoki, A., SAE Paper, No. 790265 (1979) : Weir, D. H., Zellner, J. W. and Taper, G. L., Technical Report, National Highway Trafic Safety Admimistration, May (1979) : NAGAI, M., Azdomotica, 19-6 (1983), 737 など.