Perhaps you should try some spelling variations:
hieu cach » hieu cac, chieu sach, hieu ca
doc hieu » toc thieu, hoc thieu, hoc hien
anh dung » anh dong, anh huong, ung dung
cho dang » cao dang, cho hang, cho dong
cong dan » cong tan, huong dan, cong dong
cong san » cong tac
thai cac » thoai cac, tai cac, khai cac

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 cach - ((anh dung) OR (sach dung)) cho dang ((cong dan) or (cong san)) thai cac~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc hieu cach - ((anh dung) OR (sach dung)) cho dang ((cong dan) OR (cong san)) thai cac.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doc hieu cach - ((anh dung) OR (sach dung)) cho dang ((cong dan) or (cong san)) thai cac".
• Adding a wildcard symbol may retrieve word variants: doc hieu cach - ((anh dung) OR (sach dung)) cho dang ((cong dan) or (cong san)) thai cac*.