Perhaps you should try some spelling variations:
hieu sach » chieu sach, hieu cach, dien sach
dung cong » dung trong
doc hieu » toc thieu, hoc thieu, hoc hien
cong tan » cong tac, cong san, cong thanh
tan khan » tan khang, tan nhan, toan khoan
khan cap » khan ap, than cap, khoan cam
dung su » dung cu, dung du, dung cua
dung so » dung co, dung cho, dung hoc
dung mo » dung co, dung cho

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