Key, Mary Ritchie
Tubingen Gunter Narr Verlag 1979
Buku Teks
Singapore : The SEAMEO Regional English Language Centre
Majalah, Jurnal, Buletin
New York : The Asia Society
Majalah, Jurnal, Buletin
Agrawal, Mahesh Chandra
[, Springer], 2012
eBooks
Asia Publisher, Seoul, Korea : Asia Publishers
Majalah, Jurnal, Buletin