Drake, Henry Burgess
Oxford University, 1957
Buku Teks SO
Wilson, John B.
Longmans Green , 1958
Buku Teks SO
Lerner, Laurence D.
Oxford University Press, 1954
Buku Teks SO
Eaglestone, Robert
Routledge, 2005
Buku Teks SO
Baker, Nancy L.
Modern Language Association of America, 1985
Buku Referensi