Matz, Adolph, author
South-Western Publishing Company, 1967
Buku Teks
Matz, Adolph, author
South-Western Pub. Co., 1957
Buku Teks
Philippatos, George C.
Allyn and Bacon , 1991
Buku Teks
Boyd, Harper W., Jr., author
New York, N.Y. , Harcourt Brace Jovanovich
Buku Teks
Willis, Robert
Prentice-Hall, 1987
Buku Teks