Columbia subject headings:
Contemplation--History of doctrines--20th century.
Merton, Thomas, 1915-1968.
Harvard subject headings:
Contemplation--History of doctrines--20th century.
Merton, Thomas, 1915-1968
Princeton subject headings:
Contemplation--History of doctrines--20th century.
Merton, Thomas, 1915-1968.