1. Salayiya, E.M., Easton, P.M. and Carter, J.I. (1978). Duration of breastfeeding after early initiation and frequent feeding.Lancet,2, 1141–1143
2. Taylor, E.M., Easton, P.M. and Carter, J.I. (1986). Early sucking and prolonged breastfeeding.Am. J. Dis. Child.,140, 151–154
3. Thomson, M.E., Hartsock, T.G. and Larson, C. (1979). The importance of immediate postnatal contact: its effect on breastfeeding.Can. Fam. Physician,25, 1374–1378
4. World Health Organization (WHO) (1981). Contemporary patterns of breastfeeding: report on the WHO Collaborative Study on Breast Feeding. Geneva, p. 211
5. Population Reports Series J, No. 24 (1981). Breastfeeding, fertility and family planning. The Johns Hopkins University Press, Baltimore, MD, p. 549