Seasonal cycles of human conception.

@article{Macfarlane1974SeasonalCO,
  title={Seasonal cycles of human conception.},
  author={W. M. F. Leat. D. B. Lindsay'W. V. Macfarlane},
  journal={Progress in biometeorology. Division A: Progress in human biometeorology},
  year={1974},
  volume={1 Pt 1B},
  pages={557-77, 711-3}
}