1. An epidemiologic study of preterm delivery;Berkowitz;Am. J. Epidemiol.,1981
2. Discrete Multivariate Analysis;Bishop,1975
3. Coffee, risk factor during pregnancy?;Borlee;Louvain Med.,1978
4. Caffeine content of common beverages;Bunker;J. Am. Diet. Assoc.,1979
5. The Analysis of Binary Data;Cox,1970