1. Leonard, C. G. & Thorne, C. B. J. Immun. 87, 175–188 (1961).
2. Yachnin, S. & Ruttenberg, J. M. J. clin. Invest. 44, 518–534 (1965).
3. Loos, M. & Bitter-Seurmann, D. Immunology 31, 931–934 (1976).
4. Eisen, V. & Loveday, C. Br. J. Pharmac. 39, 831–833 (1970).
5. Rent, R., Ertel, N., Eisenstein, R. & Gewurz, H. J. Immun. 114, 120–124 (1975).