Perhaps you should try some spelling variations:
thanh trung » thanh tung
thien hach » thien thanh, hien hanh
hieu cach » hieu cac, chieu sach, hieu ca
trung vat » trung va, trung van, trong vat
dung cong » dung trong
bang phan » bang nhan, bang thanh, quang phan
nang phan » nang phat, nang thanh, nang quan
vat dung » van dung, va dung, viet dung

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

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