Perhaps you should try some spelling variations:
dong huong » dong thuong, dong duong, cong huong
hieu lang » chieu sang, hieu quang, nhieu tang
chua dong » cua dong, ha dong, huy dong
nhan dan » phan dau, gian dan, nhan tai
dan chua » dan cua, doan chuan, dinh chua
toan cau » toan cao, toan ban, toan tai
toan tap » toan ban

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: ho ((hieu lang) or (hieu qua)) - nhan dan chua dong huong dan ((toan cau) or (toan tap))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ho ((hieu lang) OR (hieu qua)) - nhan dan chua dong huong dan ((toan cau) OR (toan tap)).
• Adding a wildcard symbol may retrieve word variants: ho ((hieu lang) or (hieu qua)) - nhan dan chua dong huong dan ((toan cau) or (toan tap))*.