Columbia subject headings:
Age groups.
Child development.
Parent and child.
Piaget, Jean, 1896-1980.
Sullivan, Harry Stack, 1892-1949.
Harvard subject headings:
Age groups.
Child development
Parent and child.
Piaget, Jean, 1896-1980.
Sullivan, Harry Stack, 1892-1949
Princeton subject headings:
Age groups.
Child development.
Parent and child.
Piaget, Jean, 1896-1980.
Sullivan, Harry Stack, 1893-1949.