Gregorios, Paulos
World Council of Churches, 978.
Buku Teks
Krutch, Joseph Wood, author
Random House, 1959
Buku Teks
Krutch, Joseph Wood, author
Greenwood Press, 1979
Buku Teks
Howes, Mary B., author
Academic Press, 2014
eBooks
Baumeister, Roy F., author
Thomson, 2008
Buku Teks