Perhaps you should try some spelling variations:
tinh dung » trinh dung, tin dung, tinh quang
dung lang » dung dang, dung nang, dung land
tien cong » thien cong, trien cong, tien luong
lang van » dang van, tang van, hoang van
van hieu » cao hieu
hieu luc » hieu luat, hieu qua
tin quan » tinh quang, trinh quan, lien quan
quan lan » quan luan, quan lang, quan van
van tien » toan tien, van tuan
lan van » luan van, tan van, san van

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( tinh dung lang van hieu luc ) or ( tin quan lan van tien cong ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( tinh dung lang van hieu luc ) OR ( tin quan lan van tien cong )).
• Adding a wildcard symbol may retrieve word variants: (( tinh dung lang van hieu luc ) or ( tin quan lan van tien cong ))*.