Perhaps you should try some spelling variations:
tinh khong » tinh khang, tinh huong, benh khong
dung quan » dung quang, dung luan, luong quan
hieu soat » hieu suat, hieu hoat, hieu luat
kien soat » kiem soat, bien soan, kien hoa
quan van » quan va, quan luan, quan doan
quan vo » quan vi, quan va, quan ve
vo hieu » co hieu, va hieu, cao hieu
luan » lan

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 quan vo hieu soat ) or ( tinh khong ((quan van) or (luan van)) kien soat ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( trinh dung quan vo hieu soat ) OR ( tinh khong ((quan van) OR (luan van)) kien soat )).
• Adding a wildcard symbol may retrieve word variants: (( trinh dung quan vo hieu soat ) or ( tinh khong ((quan van) or (luan van)) kien soat ))*.