Perhaps you should try some spelling variations:
quang cao » nang cao, quang nam
hieu luat » hieu qua
dung quan » dung quang, dung luan, luong quan
hieu hoat » hieu hoa, thien hoat, hieu suat
luan cao » juan cao, luan bao, luan chat
quan van » luan van, quan va, quan luan
van hieu » cao hieu

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( tin dung ((luan cao) or (quang cao)) hieu luat ) or ( tin dung quan van hieu hoat ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( tin dung ((luan cao) OR (quang cao)) hieu luat ) OR ( tin dung quan van hieu hoat )).
• Adding a wildcard symbol may retrieve word variants: (( tin dung ((luan cao) or (quang cao)) hieu luat ) or ( tin dung quan van hieu hoat ))*.