Kipping, F.B.
W & R Chambers, 1957
Buku Teks
Ouellette, Robert J., author
Prentice-Hall, 1994
Buku Teks
Brown, William H., author
Saunders College, 1997
Buku Teks
Applequist, Douglas, author
John Wiley & Sons, 1982
Buku Teks
Carnduff, John, author
John Wiley & Sons, 1978
Buku Teks