by Jacquelyn Sanders ... [and others]
The University of Chicago , 1968
Buku Teks
Neubeck, Kenneth J.
Mc Graw-Hill, 1996
Buku Teks SO
Konkle, Gail S.
Prindle, Weber & Schmidt, 1974
Buku Teks
Stephen Keck
ISEAS/BUFS, 2018
Artikel Jurnal
edited by M.G. Quibria
Published for the Asian Develoment Bank by Oxford University Press, 1995
Buku Teks