Perhaps you should try some spelling variations:
chiet tach » chieu sach
nhung cong » dung cong, thong cong, hang cong
hieu lang » chieu sang, hieu quang, nhieu tang
tranh va » tranh van, trang va, trinh va
cong tac » cong ty
phan cau » phan dau, phan cac, phan tu
toan cau » toan cao, toan ban, toan tap

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

• Performing a fuzzy search may retrieve terms with similar spellings: ho ((chiet tach) or (hieu lang)) - canh tranh va nhung cong tac ((phan cau) or (toan cau))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ho ((chiet tach) OR (hieu lang)) - canh tranh va nhung cong tac ((phan cau) OR (toan cau)).
• Adding a wildcard symbol may retrieve word variants: ho ((chiet tach) or (hieu lang)) - canh tranh va nhung cong tac ((phan cau) or (toan cau))*.