Cunningham, Chris, author
Kangaroo Press, 1996
Buku Teks
Hall, Robert T.
Harper and Row, 1971
Buku Teks
Hall, Ford P.
McGraw-Hill Book Company , 1949
Buku Teks
Forster, John, author
Cambridge University Press, 2011
Buku Teks
Forster, John, author
Cambridge University Press, 2011
Buku Teks