Columbia subject headings:
Steinbeck, John, 1902-1968. Grapes of wrath.
Harvard subject headings:
California--In literature.
Depressions in literature.
Labor camps in literature.
Migrant agricultural laborers in literature.
Rural families in literature.
Steinbeck, John, 1902-1968. Grapes of wrath
Princeton subject headings:
Steinbeck, John, 1902-1968. Grapes of wrath.