Perhaps you should try some spelling variations:
chieu sach » chinh sach, chiet tach, chieu sang
thanh tung » thanh cong
nhung cong » dung cong, thong cong, hang cong
hieu lang » chieu sang, hieu quang, nhieu tang
cong manh » cong danh, duong manh, cong thanh
toan cau » toan cao, toan ban, toan tap
tung va » trung va, tuong va, dung va

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

• Performing a fuzzy search may retrieve terms with similar spellings: doi ((chieu sach) or (hieu lang)) - thanh tung va nhung cong manh ((toan cau) or (van ban))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doi ((chieu sach) OR (hieu lang)) - thanh tung va nhung cong manh ((toan cau) OR (van ban)).
• Adding a wildcard symbol may retrieve word variants: doi ((chieu sach) or (hieu lang)) - thanh tung va nhung cong manh ((toan cau) or (van ban))*.