edited by Yip Yat-hoong
Regional Institute of Higer Education and Development, 1973
Buku Teks
Schonberger, Richard John
Prenhallindo, 1997
Buku Teks
edited by Yat-hoong Yip
Regional Institute of Higher Education and Development, 1972
Buku Teks
Massachusetts: Rockport Publishers,, 1997
Buku Teks
Korea National Tourism Corporation, 1986
Buku Teks