Gonzalez, Andrew B., author
Oxford University Press, 1984
Buku Teks
Singapore : The SEAMEO Regional English Language Centre
Majalah, Jurnal, Buletin
Richards, Jack C., author
Cambridge University Press, 2015
Buku Teks
edited by Aris Ananta, Armin Bauer, Myo Thant
Institute of South East Asia Studies, 2013
eBooks
McGraw-Hill, 1965
Buku Teks
Vikas Publishing House, 1979
Buku Teks