1. BARGMANN, W. (1954) Z. Zellforsch., 40, 49 CARNEY, F. E., Jr., and TAYLOR-ROBINSON, D. (1973)
2. CASAL, J., RUBENSTEIN, D., VOTAVA, M., and TYRRELL, D. A. J. (1970) Arch. Virusforsch., 31, 196
3. Unpublished observations;ED9N, T.; MARDH, P.-A.,1970
4. Brit;HOORN, B.; TYRRELL, D.A.J.;J. exp. Path,1965
5. KELLOGG, D. S., Jr., PEACOCK, W. L., Jr., DEACON, W. E., BROWN, L., and PIRKLE, C. I. (1963)3J. Bact., 85, 1274