Graves, Robert, author
Macmillan, 1943
Buku Referensi
Lewis, Norman
New York Harper and Row 1963
Buku Referensi
Karpin, Isabel, author
Cambridge University Press, 2012
Buku Teks
Baker, Ann, author
Cambridge University Press, 1982
Buku Teks
Baker, Ann, author
Cambridge University Press, 1982
Buku Teks