Columbia subject headings:
Astronauts--Recruiting--United States--History.
United States. National Aeronautics and Space Administration--Officials and employees--Salaries, etc.--History.
Harvard subject headings:
Astronauts--Recruiting--United States--History.
United States. National Aeronautics and Space Administration--Officials and employees--Recruiting.
Princeton subject headings:
Astronauts--United States--Recruitment--History.
United States. National Aernautics and Space Administration--Appointments, promotions, salaries, etc.--History.