title: Declining childlessness and age at marriage: a test of a hypothesis.
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D002170:Canada; D005260:Female; D005298:Fertility; D006801:Humans; D007246:Infertility / Q000453:epidemiology*; D008297:Male; D008393:Marriage; D008875:Middle Aged; D012111:Residence Characteristics