Perhaps you should try some spelling variations:
hieu quang » thieu quang, hieu quan, hieu qua
nhung cong » dung cong, thong cong, hang cong
hieu lang » chieu sang, nhieu tang, hieu van
thuong va » truong va, thong va, thuong mai
tuong va » truong va, luong va, duong va
cong tan » cong tac, cong san, cong thanh
tan toan » tan tran, tap toan, van toan
toan ban » van ban

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

• If you are trying to use Boolean operators, they must be ALL CAPS: ho ((hieu lang) OR (hieu quang)) - thanh ((tuong va) OR (thuong va)) nhung cong tan toan ban~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "ho ((hieu lang) or (hieu quang)) - thanh ((tuong va) OR (thuong va)) nhung cong tan toan ban~".
• Adding a wildcard symbol may retrieve word variants: ho ((hieu lang) or (hieu quang)) - thanh ((tuong va) OR (thuong va)) nhung cong tan toan ban*.