Perhaps you should try some spelling variations:
tuong tham » luong tham, trong thai, chong tham
hieu lang » chieu sang, hieu quang, nhieu tang
tuong tac » cong tac, luong tai, tuong lai
hang cong » dang cong, hang nong, bang cong
doi hieu » doi chieu, doc hieu, doi hien
cong dan » cong san, cong tan, huong dan
toan ban » van ban

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

• If you are trying to use Boolean operators, they must be ALL CAPS: doi hieu lang - anh ((tuong tham) OR (tuong tac)) hang cong dan ((toan ban) OR (toan tap))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doi hieu lang - anh ((tuong tham) OR (tuong tac)) hang cong dan ((toan ban) or (toan tap))~".
• Adding a wildcard symbol may retrieve word variants: doi hieu lang - anh ((tuong tham) OR (tuong tac)) hang cong dan ((toan ban) or (toan tap))*.