Perhaps you should try some spelling variations:
thanh trung » thanh tung
chiet tach » chieu sach
doi chiet » doi chieu, doi chi, doi viet
trung cua » truong cua, trung tuan, trung cap
nong dan » nong san, nguong dan, huong dan
cong dan » cong san, cong tan, huong dan
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: doi chiet tach - thanh trung cua cong ((nong dan) or (cong dan)) than cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doi chiet tach - thanh trung cua cong ((nong dan) OR (cong dan)) than cau.
• Adding a wildcard symbol may retrieve word variants: doi chiet tach - thanh trung cua cong ((nong dan) or (cong dan)) than cau*.