Perhaps you should try some spelling variations:
thanh trung » thanh tung
tieu trinh » tien trinh, trieu tinh, lieu tinh
nhung cong » dung cong, thong cong, hang cong
trung dap » trung cap, trung dai, trung dam
dap nhung » vap nhung, va nhung, dap ung
ban toan » bai toan, van toan, bao toan
ban than » ban thanh, van thanh, ban hang

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

• Performing a fuzzy search may retrieve terms with similar spellings: theo ((tieu trinh) or (tien thinh)) - thanh trung dap nhung cong ((ban toan) OR (ban than)) cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: theo ((tieu trinh) OR (tien thinh)) - thanh trung dap nhung cong ((ban toan) OR (ban than)) cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "theo ((tieu trinh) or (tien thinh)) - thanh trung dap nhung cong ((ban toan) OR (ban than)) cau".
• Adding a wildcard symbol may retrieve word variants: theo ((tieu trinh) or (tien thinh)) - thanh trung dap nhung cong ((ban toan) OR (ban than)) cau*.