Powell, Douglas H.
Little, Brown & Co., 1983
Buku Teks
Kail, Robert V., author
South-Western , 2015
Buku Teks
Newman, Barbara M.
Cengage Learning, 2018
Buku Teks
Newman, Barbara M., author
Cole Publishing, 1991
Buku Teks
Strecker, Edward A.
Macmillan, 1966
Buku Teks