Columbia subject headings:
Communism--History--Sources.
Engels, Friedrich, 1820-1895--Dictionaries.
Marx, Karl, 1818-1883--Dictionaries.
Harvard subject headings:
Communism--History--Sources.
Engels, Friedrich, 1820-1895--Dictionaries, indexes, etc.
Engels, Friedrich, 1820-1895--Dictionaries--Indexes.
Marx, Karl, 1818-1883--Dictionaries, indexes, etc.
Marx, Karl, 1818-1883--Dictionaries--Indexes.
Princeton subject headings: