Lauer, Robert H., author
Allyn and Bacon, 1982
Buku Teks
Lauer, Robert H., author
Rineka Cipta, 2003
Buku Teks
Morris, Robert, author
Columbia University Press , 1966
Buku Teks
Moore, Wilbert E. (Wilbert Ellis), author
Prentice-Hall, 1963
Buku Teks
edited by Robert A. Nisbet
Blackwell, 1972
Buku Teks