Perhaps you should try some spelling variations:
hieu sang » chieu sang, hieu quang, nhieu tang
hieu lang » chieu sang, hieu quang, nhieu tang
dung cong » dung trong
tan chinh » tai chinh, lan chinh, van chinh
cong tan » cong tac, cong san, cong thanh
chinh ca » chinh ta, chinh va, chinh tai
cong su » cong suc, cong sua, cong cu

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 sang) or (hieu lang)) - thanh cong su dung cong tan chinh ca~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc ((hieu sang) OR (hieu lang)) - thanh cong su dung cong tan chinh ca.
• Adding a wildcard symbol may retrieve word variants: doc ((hieu sang) or (hieu lang)) - thanh cong su dung cong tan chinh ca*.