Perhaps you should try some spelling variations:
luong quan » thong quan, duong qua
vuong quan » cuong quan, luong quang, thong quan
hieu luat » hieu qua
dung tan » dung toan, duong tan, dung tai
van kiem » va kiem, van kien, van hien
van hieu » cao hieu
tan van » tran van, tang van, luan van

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 tan van kiem tra ) or ( tinh ((luong quan) or (vuong quan)) van hieu luat ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( tin dung tan van kiem tra ) OR ( tinh ((luong quan) OR (vuong quan)) van hieu luat )).
• Adding a wildcard symbol may retrieve word variants: (( tin dung tan van kiem tra ) or ( tinh ((luong quan) or (vuong quan)) van hieu luat ))*.