Perhaps you should try some spelling variations:
thanh dung » thanh duong, thanh tung, thanh hung
hieu sach » chieu sach, hieu cach, dien sach
dung cong » dung trong
ban thanh » ban hanh, ban hang
doc hieu » toc thieu, hoc thieu, hoc hien
dung xay » dang xay, dung may, dung tay
van tan » van tuan, van ban, van tai

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 sach - thanh dung xay dung cong ((van tan) or (ban thanh)) cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc hieu sach - thanh dung xay dung cong ((van tan) OR (ban thanh)) cao.
• Adding a wildcard symbol may retrieve word variants: doc hieu sach - thanh dung xay dung cong ((van tan) or (ban thanh)) cao*.