Columbia subject headings:
Harvard subject headings:
Child care--Economic aspects--United States.
Day care centers--United States--Supply and demand.
Education, Preschool--United States.
Working mothers--United States
Princeton subject headings:
Child care services--Economic aspects--United States.
Child care services--United States--Statistics.
Child care services--United States.
Education, Preschool--Economic aspects--United States.
Education, Preschool--United States--Statistics.
Education, Preschool--United States.