Columbia subject headings:
Korczak, Janusz, 1878-1942--Criticism and interpretation.
Korczak, Janusz, 1878-1942--Teachings.
Harvard subject headings:
Korczak, Janusz, 1878-1942--Criticism and interpretation.--Teachings.
Korczak, Janusz, 1878-1942--Teachings.
Princeton subject headings: