1. Singer, M. & Salpeter, M. in Growth in Living Systems (ed. Zarrow, M. X.) (Basic Books, New York, 1961).
2. Carlson, B. in Neoplasia and Cell Differentiation (ed. Sherbert, G. V.) (S. Karger, Basel, 1974).
3. Tassava, R. A., Bennett, L. L. & Zitnik, G. D. J. exp. Zool. 190, 111–116 (1974).
4. Mescher, A. L. & Tassava, R. A. Devl Biol. 44, 187–197 (1975a).
5. Mescher, A. L. J. exp. Zool. 195, 117–128 (1976).