Roll, Charles W.
Seven Locks Press, 1980
Buku Teks
edited by Richard J. Schoeck and Jerome Taylorand
University of Notre Dame Press, 1968
Buku Teks
Margaretha Chrisna Sari, author
Universitas Indonesia, 2009
UI - Skripsi (Open)
Muller, Herbert J.
George Braziller, Inc., 1956
Buku Teks
Waworuntu, Adrianus Laurens Gerung, author
Fakultas Ilmu Pengetahuan dan Budaya Universitas Indonesia, 1985
UI - Skripsi (Membership)