Perhaps you should try some spelling variations:
dung chuan » dong chuan, chung chuan, dung luan
chuan doan » chan doan
tinh khong » tinh khang, tinh huong, benh khong
khong quan » thong quan, hong quan, thong quang
hieu suat » hieu luat
quan quan » quan quang, qua quan, quan luan
quan kien » quan dien, quan mien, xuan kien
kien hoa » dien hoa, tien hoa, kien ha

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 chuan doan ((hieu suat) OR (hieu qua)) ) or ( tinh khong quan quan kien hoa ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( trinh dung chuan doan ((hieu suat) OR (hieu qua)) ) OR ( tinh khong quan quan kien hoa ))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( trinh dung chuan doan ((hieu suat) OR (hieu qua)) ) or ( tinh khong quan quan kien hoa ))*".