Hudson, Ray, author
Prentice-Hall, 2000
Buku Teks
Hudson, Ray, author
Prentice-Hall, 2000
Buku Teks
Thatcher, W.S., author
English University Press, 1957
Buku Teks
Wheeler, James O., author
John Wiley & Sons, 1986
Buku Teks
Hartshorn, Truman Asa, author
Prentice-Hall, 1988
Buku Teks