Columbia subject headings:
Harvard subject headings:
Curriculum change--United States.
Education--Curricula--United States
Educational publishing--United States.
Textbooks--Publishing--Social aspects--United States.
Textbooks--United States--Authorship.
Textbooks--United States--History.
Textbooks--United States.
Princeton subject headings:
Educational publishing--United States.
Textbooks--Publishing--Social aspects--United States.
Textbooks--United States--History.
Textbooks--United States.