Columbia subject headings:
Animal rights.
Human ecology.
Human rights.
Marx, Karl, 1818-1883.
Political science.
Social ecology.
Social justice.
Harvard subject headings:
Animal rights
Human ecology
Human rights
Marx, Karl, 1818-1883--Contributions in political science.
Social ecology
Princeton subject headings:
Animal rights.
Human ecology.
Human rights.
Marx, Karl, 1818-1883--Contributions in political science.
Social ecology.