Maltzoff, Nicholas
Ellinois Passport Book, 1994
Buku Teks
Lusin, Natala
Baron's Education, 1992
Buku Referensi
Wade, Terence
New York : Oxford University Press, 2002
Buku Referensi
Timberlake, Alan
Cambridge University Press, 2004
Buku Teks SO
Murray, John D. (John Damian)
Routledge, 2001
Buku Teks