1. Fenner, F., Henderson, D. A., Arita, I., Jerzek, Z., and Ladnyi, I. D., Smallpox and its eradication, 1988, WHO, Geneva.
2. Goabel, S. C., Johnson, G. P., Perkus, M. E., Davis, S. W., Winslow, J. P., and Paoeletti, E., 1990, Virology 179:247–266.
3. Kates, J. R., and McAuslan, B. R., 1967, Proc. Natl. Acad. Sci. USA 58:134–141.
4. Munyon, W. E., Paoletti, E., and Grace, J. T., 1967, Proc. Natl. Acad. Sci. USA 58:2280–2288.
5. Kates, J. R., and Beeson, J., 1970, J. Mol. Bio. 50:19–23.