Perhaps you should try some spelling variations:
tinh quan » tinh quang, trinh quan, tin quan
quan quan » quan quang, qua quan, quan luan
tinh hang » tinh khang, minh hang, tinh hung
hang luan » tang luan, dung luan
hieu suat » hieu luat
van hieu » cao hieu
quan li » quan ly, quan tri
li hieu » ly hieu, le hieu, li hien

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: (( tinh quan quan li hieu qua ) or ( tinh hang luan van hieu suat ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( tinh quan quan li hieu qua ) OR ( tinh hang luan van hieu suat ))*.