Perhaps you should try some spelling variations:
hieu manh » chieu xanh, hieu nganh, dieu hanh
hieu lang » chieu sang, hieu quang, nhieu tang
trung cap » truong cao
dang cong » dung cong
tap quang » tap quan, tac quang, tai quang
quang cua » quan cua, quang tuan, quang huy
cong tap » cuong tap, cong tac, cong tan

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

• Performing a fuzzy search may retrieve terms with similar spellings: theo ((hieu manh) or (hieu lang)) - thanh ((trung cap) OR (trung tam)) dang cong tap quang cua~.
• If you are trying to use Boolean operators, they must be ALL CAPS: theo ((hieu manh) OR (hieu lang)) - thanh ((trung cap) OR (trung tam)) dang cong tap quang cua.
• The words AND, OR and NOT may confuse the search; try adding quotes: "theo ((hieu manh) or (hieu lang)) - thanh ((trung cap) OR (trung tam)) dang cong tap quang cua".
• Adding a wildcard symbol may retrieve word variants: theo ((hieu manh) or (hieu lang)) - thanh ((trung cap) OR (trung tam)) dang cong tap quang cua*.