Perhaps you should try some spelling variations:
hieu luat » hieu qua
tin mang » tin nang, ninh mang, tien manh
mang lam » bang lam, mang lai, mang mam
dau hieu » dao hieu, dat hieu, dau sieu
dac tinh » may tinh, ha tinh, ban tinh
lam dau » lan dau, lam giau, luat dau
dat dac » dat dai, dam dac, dai dac
tinh so » tinh son, tinh soc, dinh so

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( tin mang lam dau hieu luat ) or ( trinh luat dat dac tinh so ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( tin mang lam dau hieu luat ) OR ( trinh luat dat dac tinh so ))*.