Perhaps you should try some spelling variations:
dung land » dung luan, dung lam, dung san
hieu suat » hieu luat, hieu qua
tien soat » trien hoat, thien hoat, kiem soat
land van » lang van, lan van, luan van
van hieu » cao hieu
van quan » van ban
van tien » toan tien, van tuan

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( trinh dung land van hieu suat ) or ( binh ((tran quang) or (van quan)) van tien soat ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( trinh dung land van hieu suat ) OR ( binh ((tran quang) OR (van quan)) van tien soat )).
• Adding a wildcard symbol may retrieve word variants: (( trinh dung land van hieu suat ) or ( binh ((tran quang) or (van quan)) van tien soat ))*.