Perhaps you should try some spelling variations:
thieu xanh » chieu xanh, hieu manh, thien anh
thanh tinh » thanh binh, nhanh tinh, than kinh
nhung cong » dung cong, thong cong, hang cong
hieu lang » chieu sang, hieu quang, nhieu tang
tan toan » tap toan, van toan, dan toan
tinh va » tich va, trinh van, trinh vat

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 xanh) or (hieu lang)) - thanh tinh va nhung cong ((tan toan) or (tan tran)) tap~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((thieu xanh) OR (hieu lang)) - thanh tinh va nhung cong ((tan toan) OR (tan tran)) tap.
• Adding a wildcard symbol may retrieve word variants: hoc ((thieu xanh) or (hieu lang)) - thanh tinh va nhung cong ((tan toan) or (tan tran)) tap*.