Pulkina, I.M.
Russian Language Publishers, 1975
Buku Teks
Murray, John D. (John Damian)
Routledge, 2001
Buku Teks
Lusin, Natala
Baron's Education, 1992
Buku Referensi
Wade, Terence
New York : Oxford University Press, 2002
Buku Referensi
Smirnitsky, A.I.
Higher School Publishing House, 1975
Buku Teks