1. Hammerberg, B., Musoke, A. J., Hustead, S. T. & Williams, J. F. in Pathophysiology of Parasitic Infections (ed. Soulsby, E. J. L.) 233–240 (Academic, New York, 1976).
2. Machado, A. J., Gazzinelli, G., Pellegrino, J. & Dias Da Silva, W. Expl Parasit. 38, 20–39 (1975).
3. Jarvinem, J. A. & Dalmasso, A. P. Infection Immunity 4, 894–902 (1976).
4. Nagle, R. B. et al. Am. J. trop. Med. Hyg. 23, 15–26 (1974).
5. Kobayashi, A. & Tizard, I. R. Tropenmed. Parasit. 27, 411–417 (1976).