1. WHO Scientific Group on Viral Respiratory Diseases. WHO Technical Report Series 642: 7–49, 1980.
2. Centers for Disease Control. Morbidity and Mortality Weekly Report 35:317–331, 1986.
3. National Center for Health Statistics. Vital and Health Statistics, Series 10 141: 11–18, 1982.
4. Couch, R.B. J. Infect. Dis. 150:167–173, 1984.
5. Gwaltney, J.M. Jr., Hendley, J.O., Simon, G. and Jordan. W.S. N. Engl. J. Med. 275:1261–1268, 1966.