Williams, Tennessee
Penguin Books , 1964
Buku Teks
Wawan Christiawan
Fakultas Ilmu Pengetahuan dan Budaya Universitas Indonesia, 2002
UI - Tesis (Membership)
Pritchett, C. Herman
University of North California Press, 1943
Buku Teks
Pritchard, Jack A.
Airlangga University , 1991
Buku Teks
editors, Kenneth Kaushansky, Marshall A. Lichtman, Josef T. Prchal, Marcel Levi, Oliver W. Press, Linda J. Burns, Michael A. Caligiuri.
McGraw-Hill Education, 2016
Buku Teks