Perhaps you should try some spelling variations:
thuong cong » thong cong, thuong con, thuong dong
hieu quang » thieu quang, hieu quan, hieu qua
cua thuong » cua truong, cua phuong, ca thuong
hieu lang » chieu sang, nhieu tang, hieu van
than sinh » than kinh, nhan sinh, phan sinh
thai sinh » thai binh, phai sinh, tai sinh
cong san » cong tac
san than » sang than, san thanh, ban than
than tap » toan tap, han tap, phan tap

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 lang) OR (hieu quang)) - ((than sinh) or (thai sinh)) cua thuong cong san than tap~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ho ((hieu lang) OR (hieu quang)) - ((than sinh) OR (thai sinh)) cua thuong cong san than tap.
• The words AND, OR and NOT may confuse the search; try adding quotes: "ho ((hieu lang) OR (hieu quang)) - ((than sinh) or (thai sinh)) cua thuong cong san than tap".
• Adding a wildcard symbol may retrieve word variants: ho ((hieu lang) OR (hieu quang)) - ((than sinh) or (thai sinh)) cua thuong cong san than tap*.