Mackie, Gerry, author
Cambridge University Press, 2003
Buku Teks
Catt, Helena, author
Routledge , 1999
Buku Teks
edited by Richard M. Ketchum
Dutton, 1955
Buku Teks
Ross, Alf, author
Harvard University Press, 1952
Buku Teks
Lindsay, A.D., author
Oxford University Press, 1948
Buku Teks