Columbia subject headings:
Christianity and other religions--Islam.
Islam in literature.
Islam--Relations--Christianity.
May, Karl, 1842-1912--Criticism and interpretation.
Harvard subject headings:
Authors, Austrian--Biography.
Christianity and other religions--Islam
Islam--Relations--Christianity
May, Karl, 1842-1912--Religion and ethics.
May, Karl, 1842-1912--Religion.
Princeton subject headings: