Timberlake, Alan
Cambridge University Press, 2004
Buku Teks
Jones, Daniel
University Press, 1958
Buku Teks
Galsworthy, J Galsworthy, John
Melbourne [etc.] Heineman 1948
Buku Teks
Oettinger, Anthony G.
Harvard University Press , 1960
Buku Teks
Lewis, Norman
New York Harper and Row 1963
Buku Referensi