Perhaps you should try some spelling variations:
cong thanh » dong thanh, cong trinh, cong tan
hieu lang » chieu sang, hieu quang, nhieu tang
quan dang » quang dang, quan lang, quan dong
gian lang » gian dan
doi hieu » doi chieu, doc hieu, doi hien
van toan » van tuan, van tan, van thanh
toan cao » toan ban, toan tap

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

• Performing a fuzzy search may retrieve terms with similar spellings: doi hieu lang - thanh cong thanh ((quan dang) or (gian lang)) van toan cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doi hieu lang - thanh cong thanh ((quan dang) OR (gian lang)) van toan cao.
• Adding a wildcard symbol may retrieve word variants: doi hieu lang - thanh cong thanh ((quan dang) or (gian lang)) van toan cao*.