Perhaps you should try some spelling variations:
nhung cong » dung cong, thong cong, hang cong
thanh toan » thanh hoa, thanh san, tinh toan
hieu lang » chieu sang, hieu quang, nhieu tang
thong cua » thong quan, thong tu, huong cua
hach toan » manh toan
dung cua » dung luan, dung cho
ho hieu » ho chieu, hoi hieu, nho hieu

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: ho hieu lang - hanh ((thong cua) OR (dung cua)) nhung cong ((hach toan) OR (thanh toan)) cau~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "ho hieu lang - hanh ((thong cua) or (dung cua)) nhung cong ((hach toan) OR (thanh toan)) cau~".
• Adding a wildcard symbol may retrieve word variants: ho hieu lang - hanh ((thong cua) or (dung cua)) nhung cong ((hach toan) OR (thanh toan)) cau*.