Perhaps you should try some spelling variations:
thanh dong » thanh duong, thanh cong, hanh dong
dong quang » duong quang, dang quang, dung quang
hieu sach » chieu sach, hieu cach, dien sach
san thanh » ban thanh, van thanh, son thanh
thanh lap » thanh san, phan lap, thanh hai
doc hieu » toc thieu, hoc thieu, hoc hien

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 dong quang ((dung trong) or (dung cong)) san thanh lap~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc hieu sach - thanh dong quang ((dung trong) OR (dung cong)) san thanh lap.
• Adding a wildcard symbol may retrieve word variants: doc hieu sach - thanh dong quang ((dung trong) or (dung cong)) san thanh lap*.