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
trinh va » trinh van, trinh vat, trinh vi
trinh ve » trinh he, trinh vi, trinh viet
cong dan » cong san, cong tan, huong dan
dan chan » dan gian, dan ca, van chat
chan cao » chan cho, chat cao, chay cao

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: hoi ((hieu lang) OR (hieu quang)) - hanh ((trinh va) OR (trinh ve)) nhung cong dan chan cao~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoi ((hieu lang) or (hieu quang)) - hanh ((trinh va) OR (trinh ve)) nhung cong dan chan cao~".
• Adding a wildcard symbol may retrieve word variants: hoi ((hieu lang) or (hieu quang)) - hanh ((trinh va) OR (trinh ve)) nhung cong dan chan cao*.