Smith, R. Nelson, author
W.H. Freeman, 1980
Buku Teks
Nekrasov, B., author
Peace, 1965
Buku Teks
Burman, Harold G., author
Allyn and Bacon, 1968
Buku Teks
Will, John W., author
Prentice-Hall, 2002
Buku Teks
Pierce, Conway, author
W H Freeman, 1965
Buku Teks