1. Crawford, L., R. Dulbecco, M. Fried, L. Montagnier, and M. Stoker, these Proceedings, 52, 148 (1964).
2. Abel, P., and L. V. Crawford, Virology, 19, 470 (1963).
3. Vogt, M., and R. Dulbecco, Virology, 16, 41 (1962).
4. Winocour, E., Virology, 19, 158 (1963).
5. Vogt, M., and R. Dulbecco, these Proceedings, 49, 171 (1963).