1. Montagnier, L., Path. Biol., Paris, 14, 244–251 (1966).
2. Stoker, M., O'Neill, C., Berryman, S., and Waxman, V., Int. J. Cancer, 3, 683–693 (1968).
3. Todaro, G. J., Lazar, G. K., and Green, H., J. cell. comp. Physiol., 66, 325–333 (1965).
4. Temin, H., Int. J. Cancer, 3, 771–787 (1968).
5. Bürk, R. R., in Growth regulating substances for Animal Cells (edit. by Defendi, V., and Stoker, M.), 39–50 (Wistar Institute Press, Philadelphia, 1967).