Perhaps you should try some spelling variations:
dung quan » dung quang, luong quan, dang quang
hieu soat » hieu suat, hieu hoat, kiem soat
hieu luat » hieu qua
luan khoa » khuan khoa, toan khoa, luan hoan
khoa dieu » hoc dieu
dieu soat » kiem soat, hieu suat, dieu hoa
quan cao » quang cao, quan cau, quan ao
tin » tinh

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