Murdock, George Peter, author
The Free Press, 1965
Buku Teks
Murdock, George Peter, author
Macmillan, 1960
Buku Teks
Brym, Robert J., author
Wadsworth and Cengage Learning, 2013
Buku Teks
Lundberg, George Andrew
D. McKay Co, 1964
Buku Teks
Stuart, Peter C.
Far horizon books, 1989
Buku Teks