Columbia subject headings:
Social service--Library resources--United States.
Social service--Reference books.
Social service--United States--Bibliography.
Harvard subject headings:
Social service--Library resources.
Social service--Reference books--Bibliography.
Social service--Reference books.
Social service--United States--Bibliography.
Social service--United States--Library resources.
Princeton subject headings:
Reference books--Social service.
Social service--Library resources--United States.
Social service--United States--Bibliography.