1. The sudden infant death syndrome
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3. 4. F. Biering-Sorensen, J. Hilden, and K. Biering-Sorensen : Breast-feeding in Copenhagen 1938-1972. Data for more than 360 000 infants. To be published.
4. 5. F. Biering-Sorensen, T. Jorgensen, and J. Hilden : Sudden infant death in Copenhagen 1956-1971. II. Social factors and morbidity. To be published.