Perhaps you should try some spelling variations:
cong thanh » dong thanh, cong trinh, cong tan
thong dung » thong cong, thong thuong
dung thanh » duong thanh, dong thanh, dang thanh
trong mach » trong cac, trong minh, trong anh
hieu lang » chieu sang, hieu quang, nhieu tang
cong tuan » cong tan, cong luan, cong quang
trong bau » trong ban, trong ba, trong dau
nho hieu » nha hieu, nho sieu, nhu hieu

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

• Performing a fuzzy search may retrieve terms with similar spellings: nho hieu lang - thanh ((cong tuan) OR (cong thanh)) thong dung thanh ((trong mach) or (trong bau))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: nho hieu lang - thanh ((cong tuan) OR (cong thanh)) thong dung thanh ((trong mach) OR (trong bau)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "nho hieu lang - thanh ((cong tuan) OR (cong thanh)) thong dung thanh ((trong mach) or (trong bau))".
• Adding a wildcard symbol may retrieve word variants: nho hieu lang - thanh ((cong tuan) OR (cong thanh)) thong dung thanh ((trong mach) or (trong bau))*.