Physician specialist growth into the 21st century.
D006801:Humans; D007388:Internal Medicine / Q000639:trends; D010820:Physicians / Q000600:supply & distribution* / Q000639:trends; D010821:Physicians, Family / Q000600:supply & distribution / Q000639:trends; D013038:Specialization / Q000639:trends*; D014481:United States; D000078329:Workforce