Perhaps you should try some spelling variations:
thanh trung » thanh tung
chieu sach » chinh sach, chiet tach, chieu sang
tuong cong » truong cong, trong cong, tong cong
hieu lang » chieu sang, hieu quang, nhieu tang
trung va » truong va, trang va, trung ha
va tuong » va thuong, va thong, xa truong
cong tan » cong tac, cong san, cong thanh
tan toan » tan tran, tap toan, van toan
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: doi ((chieu sach) or (hieu lang)) - thanh trung va tuong cong tan toan cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doi ((chieu sach) OR (hieu lang)) - thanh trung va tuong cong tan toan cao.
• Adding a wildcard symbol may retrieve word variants: doi ((chieu sach) or (hieu lang)) - thanh trung va tuong cong tan toan cao*.