title: The length of the human fertile period.
abstract: Abstract   Estimates of the. length of the human fertile period (that interval within the menstrual cycle during which insemination is associated with a non-zero probability of conception) are necessarily indirect. Moreover, those estimates do not seem in close agreement with one another. For instance, it has been suggested that:
authors.forename: W H
authors.initials: WH
authors.lastname: James