Columbia subject headings:
Engels, Friedrich, 1820-1895.
Marx, Karl, 1818-1883.
Harvard subject headings:
Engels, Friedrich, 1820-1895
Marx, Karl, 1818-1883
Princeton subject headings:
Engels, Friedrich, 1820-1895--Criticism and interpretation.
Marx, Karl, 1818-1883--Criticism and interpretation.
Marx, Karl, 1818-1883. Deutsche Ideologie.
Marx, Karl, 1818-1883. Kapital.