Perhaps you should try some spelling variations:
quang luan » quang tuan, quang uan, quang xuan
minh thong » minh thuong, minh tuong, minh thang
hieu suat » hieu luat, hieu qua
lien soat » kiem soat, bien soan, lien son
van hieu » cao hieu
quan doi » quan tri, quan li
doi lien » doi dien, doi bien, doi hien

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( kinh ((quang luan) or (quan luan)) van hieu suat ) or ( minh thong quan doi lien soat ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( kinh ((quang luan) OR (quan luan)) van hieu suat ) OR ( minh thong quan doi lien soat )).
• Adding a wildcard symbol may retrieve word variants: (( kinh ((quang luan) or (quan luan)) van hieu suat ) or ( minh thong quan doi lien soat ))*.