Perhaps you should try some spelling variations:
tinh dung » trinh dung, tin dung, tinh quang
dung quan » dung quang, dung luan, luong quan
hieu soat » hieu suat, hieu luat, kiem soat
hieu hoat » hieu hoa, thien hoat, hieu luat
lieu soan » lieu lon, bien soan, lieu quan
tin nang » tin dung, ki nang, thi nang
suat vat » suat va, xuat vat, thuat vat

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 quan luan ((hieu soat) OR (hieu hoat)) ) or ( tin nang suat vat lieu soan ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( tinh dung quan luan ((hieu soat) OR (hieu hoat)) ) OR ( tin nang suat vat lieu soan )).
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( tinh dung quan luan ((hieu soat) OR (hieu hoat)) ) or ( tin nang suat vat lieu soan ))".
• Adding a wildcard symbol may retrieve word variants: (( tinh dung quan luan ((hieu soat) OR (hieu hoat)) ) or ( tin nang suat vat lieu soan ))*.