1. Bradford, S. C., Documentation (Crosby Lockwood, London, 1948).
2. Selye, H., The Mast Cells (Butterworth, London, 1968).
3. Goffman, W., Nature, 212, 449 (1966).
4. Warren, K. S., and Newill, V. A., Schistosomiasis, a Bibliography of the World's Literature from 1852–1962 (Western Reserve University Press, Cleveland, 1967).
5. Leimkuhler, F. F., J. Doc., 25, 197.