Ross, David
Methuen, [t.th.]
Buku Teks
Allan, D.J.
Oxford University,, 1957
Buku Teks
Cooper, Lane
Appleton-Century-Crofts, 1932
Buku Teks
Adler, Mortimer Jerome, 1902-2001, author
Macmillan, 1979
Buku Teks
Echenique, Javier, author
Cambridge University Press, 2012
Buku Teks