Columbia subject headings:
Geriatrics--Encyclopedias.
Older people--Diseases--Encyclopedias.
Older people--Health and hygiene--Encyclopedias.
Harvard subject headings:
Geriatrics--Encyclopedias.
Older people--Diseases--Encyclopedias.
Older people--Health and hygiene--Encyclopedias.
Princeton subject headings:
Encyclopedias.
Older people--Medical care--United States--Encyclopedias.
Public health--United States--Encyclopedias.