Niebuhr, Reinhold, author
Charles Scribners Sons, 1945
Buku Teks
Niebuhr, Reinhold, author
Nisbet & Co., 1946
Buku Teks
Cupitt, Don
Sheldon Press, 1979
Buku Teks
Odum, Howard T., author
McGraw-Hill, 1981
Buku Teks
Royce, James E.
McGraw-Hill, 1961
Buku Teks