Greene, Judith, author
Open University Press, 2006
Buku Teks
Deese, James, author
McGraw-Hill, 1967
Buku Teks
Ferguson, George Andrew, author
McGraw-Hill , 1981
Buku Teks
Ferguson, George Andrew, author
McGraw-Hill, 1987
Buku Teks
Ferguson, George Andrew, author
McGraw-Hill , 1989
Buku Teks