Holes, Clive
Longman, 1995
Buku Teks
Brustad, Kristen
Georgetown University Press, 1995
Buku Teks
Alosh, Mahdi
Yale University Press, 2000
Buku Teks
Ryding, Karin C
Cambridge University Press, 2013
Buku Teks
Wehr, Hans, 1909-1981
Spoken Language Services, 1976
Buku Referensi