1. Baker, E. R., Mathur, R. S., Kirk, R. F., and Williamson, H. O. (1981). Female runners and secondary amenorrhea: Correlations with age, parity, mileage, and plasma hormonal and sex-hormone binding globulin concentrations.Fertility and Sterility 36: 183?187.
2. Bedale, E. M. (1924). Comparison of the energy expenditure of a woman, carrying loads in eight different positions. Industrial Fatigue Research Board Report No. 29, pp. 1?27.
3. Bedford, T., and Warner, C. G. (1955). The energy expended while walking in stooping postures.British Journal of Industrial Medicine 12: 290?295.
4. Bicchieri, M. G. (ed.). (1972).Hunters and Gatherers Today: A Socioeconomic Study of Eleven Such Cultures in the Twentieth Century. Holt, Rinehart and Winston, New York.
5. Billewicz, W. H. (1979). The timing of post-partum menstruation and breast-feeding: A simple formula.Journal of Biosocial Science 11: 141?151.