1. Blaskovic, D., and Rehacek, J., in Biological Transmission of Disease Agents, 135 (Academic Press, New York, 1962).
2. Benda, R., J. Hyg. Epidem. (Prague), 2, 314 (1958).
3. Smorodintsev, A. A., Prog. Med. Virol., 1, 210 (1958).
4. Rehacek, J., Acta Virol., 6, 220 (1962).