Columbia subject headings:
Harvard subject headings:
Education--Philosophy
Education--Study and teaching
Fröbel, Friedrich, 1782-1852--Correspondence.
Fröbel, Friedrich, 1782-1852.
Princeton subject headings:
Education--Philosophy.
Education--Study and teaching.
Fröbel, Friedrich, 1782-1852--Correspondence.
Fröbel, Friedrich, 1782-1852.