Perhaps you should try some spelling variations:
nhanh bang » nhanh lang, nhanh mang, nhanh quang
hieu lang » chieu sang, hieu quang, nhieu tang
van thanh » ban thanh, van tuan
va duong » van duong, va tuong, va huong
van toan » van tuan, van tan, manh toan
ho hieu » ho chieu, hoi hieu, nho hieu
va dung » van dung, vat dung, va ung

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

• Performing a fuzzy search may retrieve terms with similar spellings: ho hieu lang - nhanh bang ((va dung) OR (va duong)) cong ((van toan) or (van thanh)) cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ho hieu lang - nhanh bang ((va dung) OR (va duong)) cong ((van toan) OR (van thanh)) cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "ho hieu lang - nhanh bang ((va dung) OR (va duong)) cong ((van toan) or (van thanh)) cau".
• Adding a wildcard symbol may retrieve word variants: ho hieu lang - nhanh bang ((va dung) OR (va duong)) cong ((van toan) or (van thanh)) cau*.