Perhaps you should try some spelling variations:
phuong cong » phuong dong, phong cong, phung cong
hieu lang » chieu sang, hieu quang, nhieu tang
doi hieu » doi chieu, doc hieu, doi hien
tranh va » tranh van, trang va, thanh va
trinh va » trinh van, trinh vat, trinh ve
dan toan » van toan, dan than, manh toan
dan chan » dan gian, dan ca, van chat

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

• Performing a fuzzy search may retrieve terms with similar spellings: doi hieu lang - canh ((tranh va) or (trinh va)) phuong cong ((dan toan) or (dan chan)) cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doi hieu lang - canh ((tranh va) OR (trinh va)) phuong cong ((dan toan) OR (dan chan)) cau.
• Adding a wildcard symbol may retrieve word variants: doi hieu lang - canh ((tranh va) or (trinh va)) phuong cong ((dan toan) or (dan chan)) cau*.