Farrow, David, author
McGraw-Hill, 1994
Buku Teks
Smith, Jay M., author
South-Western Publishing, 1982
Buku Teks
Simons, Harry, author
South-Western Publishing, 1977
Buku Teks
Pizzey, Alan, author
Holt, Rinehart and Winston , 1980
Buku Teks
Williams, Robert I., editor
Prentice-Hall, 1956
Buku Referensi