Perhaps you should try some spelling variations:
dong quang » duong quang, dang quang, dung quang
hieu tinh » chieu tinh, lieu tinh, kieu tinh
bien tinh » bi tinh, yen tinh, diep tinh
quang dan » quang dang, quang doan, quang ban
cong dan » cong san, cong tan, huong dan
dan cong » dang cong, van cong, dan dong

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

• Performing a fuzzy search may retrieve terms with similar spellings: doc ((hieu tinh) or (bien tinh)) - thanh cong dan cong dong quang dan ca~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc ((hieu tinh) OR (bien tinh)) - thanh cong dan cong dong quang dan ca*.