Bianki, V.
Foreign Languages Publishing, [date of publication not identified]
Buku Teks
Wallwork, Adrian
Springer, 2010
Buku Teks
Emmerson, Paul
Cambridge University Press, 2005
Buku Teks
Cellich, Claude
Business Expert Press, 2012
Buku Teks
Moran, Robert T.
Gulf, 1991
Buku Teks