Tyler, E. T. 1953. Physiological and Clinical Aspects of Conception. J Am Med Ass 153: 1351–1356.

Udry, J. R., and N. M. Morris. 1967. Seasonality of Coitus and Seasonality of Birth. Demography 4: 673–679.

______. 1968. Distribution of Coitus in the Menstrual Cycle. Nature 220: 593–596.

______. 1977. The Distribution of Events in the Human Menstrual Cycle. J Re-prod Fertil 51: 419–425.

Vandenberg, L. N., I. Chahoud, J. J. Heindel, V. Padmanabhan, F. J. R. Paumgartten, and G. Schoenfelder. 2010. Urinary, Circulating, and Tissue Biomonitoring Studies Indicate Widespread Exposure to Bisphenol A. Environm Health Perspect 118: 1055–1070.

van Os, J. L., M. J. de Vries, N. H. den Daas, and L. M. K. Lansbergen. 1997. Longterm Trends in Sperm Counts in Dairy Bulls. J Androl 18: 725–731.

Vennemann, M. M., T. Bajanowski, B. Brinkmann, G. Jorch, K. Yücesan, C. Sauerland, E. A. Mitchell, and the GeSID Study Group. 2009. Does Breastfeeding Reduce the Risk of Sudden Infant Death Syndrome? Pediatrics 123: e406–e410.

Viterbo, P. 2004. I Got Rhythm: Gershwin and Birth Control in the 1930s.

Endeavour 28: 30–35.

Vitzthum, V. J. 1994. Comparative Study of Breastfeeding Structure and Its Rela-tion to Human Reproductive Ecology. Yearb Phys Anthropol 37: 307–349.

von Holst, D. 1974. Social Stress in the Tree-Shrew: Its Causes and Physiological and Ethological Consequences. In Prosimian Biology, ed. R. D. Martin, G. A. Doyle, and A. C. Walker, 389–411. London: Duckworth.

Waldinger, M. D., P. Quinn, M. Dilleen, R. Mundayat, D. H. Schweitzer, and M. Boolell. 2005. A Multinational Population Survey of Intravaginal Ejaculation Latency Time. J Sex Med 2: 492–497.

Wang, Y. S., and S. Y. Wu. 1996. The Efect of Exclusive Breastfeeding on Development and Incidence of Infection in Infants. J Hum Lact 12: 27–30.

Weaver, T. D., and J.-J. Hublin. 2009. Neandertal Birth Canal Shape and the Evolution of Human Childbirth. Proc Natl Acad Sci USA 106: 8151–8156.

Wehr, T. A. 1991. The Durations of Human Melatonin Secretion and Sleep Respond to Changes in Daylength (Photoperiod). J Clin Endocrinol Metab 73: 1276–1280.

______. 2001. Photoperiodism in Humans and Other Primates: Evidence and Implications. J Biol Rhythms 16: 348–364.

Wehr, T. A., H. A. Giesen, D. E. Moul, E. H. Turner, and P. J. Schwartz. 1995. Suppression of Men’s Responses to Seasonal Changes in Day-Length by Modern Artificial Lighting. Am J Physiol 269: R173–R178.

Weigel, R. M., and M. M. Weigel. 1989. Nausea and Vomiting of Early Pregnancy and Pregnancy Outcome: A Meta-analytical Review. Brit J Obstet Gynaecol 96: 1312–1318.

Weiss, K. 2004. The Frog in Tafeta Pants. Evol Anthropol 13: 5–10.

Westof, C. F. 1976. The Decline of Unplanned Births in the United States. Sci-ence 91: 38–41.

Whitcome, K., and D. E. Lieberman. 2007. Fetal Load and the Evolution of Lumbar Lordosis in Bipedal Hominins. Nature 450: 1075–1078.

White, D. R., E. M. Widdowson, H. Q. Woodard, and J. W. T. Dickerson. 1991. The Composition of Body Tissues (II). Fetus to Young Adult. Brit J Radiol 64: 149–159.

Wickings, E. J., and E. Nieschlag. 1980. Seasonality in Endocrine and Exocrine Function of the Adult Rhesus Monkey (Macaca mulatta) Maintained in a Controlled Laboratory Environment. Int J Androl 3: 87–104.

Wilcox, A. J., D. D. Baird, D. B. Dunson, D. R. McConnaughey, J. S. Kesner, and C. R. Weinberg. 2004. On the Frequency of Intercourse Around Ovulation: Evidence for Biological Influences. Hum Reprod 19: 1539–1543.

Wilcox, A. J., D. Dunson, and D. D. Baird. 2000. The Timing of the “Fertile Window” in the Menstrual Cycle: Day Specific Estimates from a Prospective Study. Brit Med J 321: 1259–1262.

Wilcox, A. J., C. R. Weinberg, J. F. O’Connor, D. D. Baird, J. P. Schlatterer, R. E. Canfield, E. G. Armstrong, and B. C. Nisula. 1988. Incidence of Early Loss of Pregnancy. New Engl J Med 319: 189–194.

Williams, G. C., and R. M. Nesse. 1991. The Dawn of Darwinian Medicine.

Quart Rev Biol 66: 1–22.

Williams, M., C. J. Hill, I. Scudamore, B. Dunphy, I. D. Cooke, and C. L. R. Barratt. 1993. Sperm Numbers and Distribution Within the Human Fallopian Tube Around Ovulation. Hum Reprod 8: 2019–2026.

Wittmann, M., J. Dinich, M. Merrow, and T. Roenneberg. 2006. Social Jetlag: Misalignment of Biological and Social Time. Chronobiol Int 23: 497–509.

Wolf, D. P., W. Byrd, P. Dandekar, and M. M. Quigley. 1984. Sperm Concentration and the Fertilization of Human Eggs In Vitro. Biol Reprod 31: 837–848.

Wolf, P. H. 1968a. The Serial Organization of Sucking in the Young Infant. Pediatrics 42: 943–956.

______. 1968b. Sucking Patterns of Infant Mammals. Brain Behav Evol 1: 354–367.

Wood, J. W. 1989. Sperm Longevity. Oxf Rev Reprod Biol 11: 61–109.

Wood, S., A. Quinn, S. Troupe, C. Kingsland, and I. Lewis-Jones. 2006. Seasonal Variation in Assisted Conception Cycles and the Influence of Photoperiodism on Outcome in In Vitro Fertilization Cycles. Hum Fertil 9: 223–229.

Work Group on Breastfeeding. 1997. Breastfeeding and the Use of Human Milk. Pediatrics 100: 1035–1039.

World Health Organisation. 1985. Appropriate Technology for Birth. Lancet 326: 436–437.

Wright, L. E., and H. P. Schwarcz. 1998. Stable Carbon and Oxygen Isotopes in Human Tooth Enamel: Identifying Breastfeeding and Weaning in Prehistory. Am J Phys Anthropol 106: 1–18.

Yang, C. P. 1993. History of Lactation and Breast Cancer Risk. Am J Epidemiol 138: 1050–1056.

Yoshida, Y. 1960. Studies on Single Insemination with Donor’s Semen. J Jap Obstet Gynecol Soc 7: 19–34.

Young, S. M., D. C. Benyshek, and P. Lienard. 2012. The Conspicuous Absence of Placenta Consumption in Human Postpartum Females: The Fire Hypothesis. Ecol Food Nutr 51: 198–217.

Zalko, D., C. Jacques, H. Duplan, S. Bruel, and P. Perdu. 2011. Viable Skin Efficiently Absorbs and Metabolizes Bisphenol A. Chemosphere 82: 424–430.

Zeilmaker, G. H., A. T. Alberda, I. Vangent, C. M. P. M. Rijkmans, and A. C. Drogendijk. 1984. 2 Pregnancies Following Transfer of Intact Frozen-Thawed Embryos. Fertil Steril 42: 293–296.

Zhang, X., C. Zhu, H. Lin, Q. Yang, Q. Ou, Y. Li, Z. Chen, P. Racey, S. Zhang, and H. Wang. 2007. Wild Fulvous Fruit Bats (Rousettus leschenaulti) Exhibit Humanlike Menstrual Cycle. Biol Reprod 77: 358–364.