1. HOSHINO, O., TANZAWA, K., HASEGAWA, Y. and UKIYA, T., Eisei Kagaku, 12, 90 (1966) (in Japanese)
2. SUMINO, K., Kobe J. Med. Sci., 14, 131(1968)
3. EKMAN, L., GREITZ, U., PERSSON, G. and ABERG, B., Nordisk Med., 79, 450 (1968) (in Swedish)
4. MIETTINEN, J. K., RAHOLA, T., HATTULA, T., RISSANEN, K. and TILLANDER, M., Mimeograph, a preliminary paper presented at 4th Annual Meeting of Finnish Med. Soc. (1970)
5. SWENSSON, A. and ULFVARSON, U., Acta pharmacol. toxicol., 26, 273 (1968)