Columbia subject headings:
Harvard subject headings:
Education--Experimental methods
Education--Philosophy
Freinet, Célestin.
Korczak, Janusz, 1878-1942
Makarenko, Anton Semenovich, 1888-1939
Princeton subject headings:
Education--Experimental methods.
Education--Philosophy.
Freinet, Célestin.
Korczak, Janusz, 1878-1942.
Makarenko, Anton Semenovich, 1888-1939.