Backhouse, Roland C., author
Prentice-Hall, 1979
Buku Teks
Appleby, Doris, author
McGraw-Hill, 1991
Buku Teks
Jhon Wiley & Sons , 1991
Buku Teks
Cherry, Edith
John Wiley & Sons, 1999
Buku Teks
Roberts, Ian, author
Oxrord University Press, 2007
Buku Teks