Perhaps you should try some spelling variations:
thanh trung » thanh tung
hieu quang » thieu quang, hieu quan, hieu qua
hieu lang » chieu sang, nhieu tang, hieu van
trung cap » truong cao, trung tam
dung cong » dung trong
tran chau » tranh chap, tran huu
cap dung » ap dung, cao dung, chan dung
cong tan » cong tac, cong san, cong thanh
toan cau » toan cao, toan ban, toan tap

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 trung cap dung cong tan ((tran chau) OR (toan cau))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "ho ((hieu lang) OR (hieu quang)) - thanh trung cap dung cong tan ((tran chau) or (toan cau))~".
• Adding a wildcard symbol may retrieve word variants: ho ((hieu lang) OR (hieu quang)) - thanh trung cap dung cong tan ((tran chau) or (toan cau))*.