Morrison, Robert Thornton, author
Allyn and Bacon, 1973
Buku Teks
Applequist, Douglas, author
John Wiley & Sons, 1982
Buku Teks
Carnduff, John, author
John Wiley & Sons, 1978
Buku Teks
Jurch, George R., author
Burgess, 1975
Buku Teks
Mukherji, S.M., author
New Age International , 1997
Buku Teks