Ryan, A. S., Pratt, W. F., Wysong, J. L., Lewandowski, G., McNally, J. W., & Krieger, F. W. (1991). A comparison of breast-feeding data from the National Surveys of Family Growth and the Ross Laboratories Mothers Surveys.

Ryan, A S., W F. Pratt, J L. Wysong, G. Lewandowski, J W. McNally, und F W. Krieger. A Comparison of Breast-feeding Data From the National Surveys of Family Growth and the Ross Laboratories Mothers Surveys. 1991.

Ryan, A S., et al. A Comparison of Breast-feeding Data From the National Surveys of Family Growth and the Ross Laboratories Mothers Surveys. 1991.