Columbia subject headings:
Ability, Influence of age on.
Age and employment.
Life span, Productive.
Older people--Employment--United States.
Harvard subject headings:
Ability, Influence of age on.
Age and employment.
Life span, Productive
Older people--Employment--United States.
Princeton subject headings:
Ability, Influence of age on.
Age and employment.
Life span, Productive.
Older people--Employment--United States.