Columbia subject headings:
Harvard subject headings:
Academic achievement--United States
Education--Curricula--United States
Education--Curricula--United States.
Schedules, School--United States.
School day--United States.
School management and organization
School management and organization--United States
School year--United States.
Princeton subject headings:
Education--Curricula--United States.
Schedules, School--United States.
School management and organization--United States.
School year--United States.