Perhaps you should try some spelling variations:
cong thanh » dong thanh, cong trinh, cong tan
thanh pham » thanh phan, thanh pho, thanh hai
hieu sang » chieu sang, hieu quang, nhieu tang
hieu lang » chieu sang, hieu quang, nhieu tang
luan dang » luan nang, luan danh, luan dong
van nang » van quang, van ban, van dong
pham ca » pham can, pham ma, pham va

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

• Performing a fuzzy search may retrieve terms with similar spellings: doc ((hieu sang) or (hieu lang)) - kinh doanh ((luan dang) or (van nang)) cong thanh pham ca~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc ((hieu sang) OR (hieu lang)) - kinh doanh ((luan dang) OR (van nang)) cong thanh pham ca.
• Adding a wildcard symbol may retrieve word variants: doc ((hieu sang) or (hieu lang)) - kinh doanh ((luan dang) or (van nang)) cong thanh pham ca*.