Perhaps you should try some spelling variations:
thanh trung » thanh tung
thieu hach » thien hach, hieu cach, thieu cac
chieu sach » chinh sach, chiet tach, chieu sang
trung cua » truong cua, trung tuan, trung cap
cua dung » cua dang, cua dong, qua dung
cong dan » cong san, huong dan, cong dong
cong tan » cong tac, cong san, cong thanh
than cau » toan cau, phan cau, than cap

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: hoc ((thieu hach) or (chieu sach)) - thanh trung cua dung ((cong dan) OR (cong tan)) than cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((thieu hach) OR (chieu sach)) - thanh trung cua dung ((cong dan) OR (cong tan)) than cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((thieu hach) or (chieu sach)) - thanh trung cua dung ((cong dan) OR (cong tan)) than cau".
• Adding a wildcard symbol may retrieve word variants: hoc ((thieu hach) or (chieu sach)) - thanh trung cua dung ((cong dan) OR (cong tan)) than cau*.