Columbia subject headings:
Apologetics--History--20th century.
Lewis, C. S. (Clive Staples), 1898-1963.
Harvard subject headings:
Apologetics--History--20th century
Apologetics.
Christian literature, English--History and criticism.
Lewis, C. S. (Clive Staples), 1898-1963
Lewis, C. S. (Clive Staples), 1898-1963--Religion.
Princeton subject headings:
Apologetics--History--20th century.
Lewis, C. S. (Clive Staples), 1898-1963.