title: Low-income families: fertility in 1971-1972.
mesh_terms: D001741:Black or African American; D001723:Birth Rate; D005193:Family Planning Services; D005260:Female; D006801:Humans; D008427:Maternal Health Services; D011203:Poverty; D013997:Time Factors; D014481:United States; D014505:Urban Population; D044465:White People