Perhaps you should try some spelling variations:
thanh trung » thanh tung
hieu sach » chieu sach, hieu cach, dien sach
trung gap » trung cap, trung gay, trung lap
gap trong » ap trong, gay trong, lap trong
doc hieu » toc thieu, hoc thieu, hoc hien
cong dan » cong tan, huong dan, cong dong
cong san » cong tac
toan ban » van ban
khan cap » khan ap, than cap, khoan cam

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 trung gap trong ((cong dan) OR (cong san)) ((toan ban) or (khan cap))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc hieu sach - thanh trung gap trong ((cong dan) OR (cong san)) ((toan ban) OR (khan cap)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "doc hieu sach - thanh trung gap trong ((cong dan) OR (cong san)) ((toan ban) or (khan cap))".
• Adding a wildcard symbol may retrieve word variants: doc hieu sach - thanh trung gap trong ((cong dan) OR (cong san)) ((toan ban) or (khan cap))*.