Nightingale, Virginia
Routledge, 1996
Buku Teks
Abdelrahman Tareq Sadeq Elsharqawy
Graduate School of Language and Culture, Osaka University, 2019
Artikel Jurnal
Lee, Kim Chew
ISEAS Publishing, Singapore : Mainland Press, 2015
Buku Teks
Giles, Judy
Blacwell Publisher, 2008
Buku Teks
Kukkonen, Karin, 1980-
Wiley Blackwell, 2013
Buku Teks