Perhaps you should try some spelling variations:
thanh trung » thanh tung
hieu quang » thieu quang, hieu quan, diep quang
trung ha » trung hoc, trung tam, trung cap
cong van » cong vang, song van, cong tan
cong san » cong tac
toan cao » toan ban, toan tap
ha tang » phap tang, cao tang, kho tang

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

• Performing a fuzzy search may retrieve terms with similar spellings: ho ((hieu quang) or (hieu qua)) - thanh trung ha tang ((cong van) OR (cong san)) toan cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ho ((hieu quang) OR (hieu qua)) - thanh trung ha tang ((cong van) OR (cong san)) toan cao.
• The words AND, OR and NOT may confuse the search; try adding quotes: "ho ((hieu quang) or (hieu qua)) - thanh trung ha tang ((cong van) OR (cong san)) toan cao".
• Adding a wildcard symbol may retrieve word variants: ho ((hieu quang) or (hieu qua)) - thanh trung ha tang ((cong van) OR (cong san)) toan cao*.