title: Biologist Paul R. Ehrlich. Six billion and counting.
authors.forename: J
authors.initials: J
authors.lastname: Lewis
mesh_terms: D001695:Biology / Q000266:history; D004782:Environmental Health / Q000266:history; D049673:History, 20th Century; D006801:Humans; D011156:Population Density; D014481:United States