Perhaps you should try some spelling variations:
thong cong » trong cong, tong cong, thong thong
hieu lang » chieu sang, hieu quang, nhieu tang
hanh dinh » thanh dinh, hinh dinh, hanh tinh
hang cong » dang cong, hang nong, bang cong
luat data » luat dat, luat dan, luat dau
doi hieu » doi chieu, doc hieu, doi hien

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 - hanh dinh van ((thong cong) or (hang cong)) trinh luat data~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doi hieu lang - hanh dinh van ((thong cong) OR (hang cong)) trinh luat data*.