Jones, Emrys
Oxford University Press, 1970
Buku Teks
Tikhomirav, M.
Foreign Languages Publishing House, 1959
Buku Teks
Alexander, Christopher
Oxford University Press, 1977
Buku Referensi
Parfect, Michael
Routledge, 1997
Buku Teks
Redstone, Louis G.
New York: McGraw-Hill, 1976
Buku Teks