Clark, G. Kitson
Methuen & Co., Ltd., 1962
Buku Teks
Ashley, Maurice, author
Penguin Books, 1952
Buku Teks
Oakland, John, author
Routledge , 1992
Buku Teks
Oakland, John, author
London; New York Routledge 1992,
Buku Teks
Smellie, K.B.
Frederick A. Preager 1955 , 1955
Buku Teks