Perhaps you should try some spelling variations:
duong bien » duong vien, duong tien, cuong bien
quan duong » tuan duong, quan dong, qua duong
tinh dung » trinh dung, tin dung, tinh quang
hieu soat » hieu suat, hieu hoat, kiem soat
hieu luat » hieu qua
tinh nang » trinh nang, tin nang, tich nang
nang quan » ban quan, nang suat
bien soan » bien so
luan cao » juan cao, luan bao, quang cao

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