J.A. Badmin et al., J. Chromatog. 172, 319, 1979. J. Duteil et al., Therapie 30, 207, 1975; G. Rosas et al., Angiology 32, 291, 1981; S.P. Clissold et al., Drugs 33, 430, 1987; F. Briguglio et al., J. Int. Med. Res. 13, 131, 1985; G. Leonardo et al., Curr. Ther. Res. 36, 1016, 1984; F. Briguglio et al., ibid. 14, 115, 1986.