Perhaps you should try some spelling variations:
chieu sach » chinh sach, chiet tach, chieu sang
thanh tung » thanh cong
hieu lang » chieu sang, hieu quang, nhieu tang
vap thong » va thong, phap thong, khap thong
van thong » van thuong, van phong, va thong
cong san » cong tac
san phan » san pham, van phan, sat phan
phan cau » phan dau, phan cac, phan tu

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

• Performing a fuzzy search may retrieve terms with similar spellings: ho ((chieu sach) or (hieu lang)) - thanh tung ((vap thong) OR (van thong)) cong san phan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ho ((chieu sach) OR (hieu lang)) - thanh tung ((vap thong) OR (van thong)) cong san phan cau*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "ho ((chieu sach) or (hieu lang)) - thanh tung ((vap thong) OR (van thong)) cong san phan cau*".