Perhaps you should try some spelling variations:
trinh tang » trinh trang, trinh tong, trinh bang
hieu suat » hieu luat, hieu qua
tang luan » dung luan
kiem soat » kiem toan
quan so » quan su, quan doi, quan sat
quan ao » quang cao, quang bao, quan doi
luan va » luan van, luat va
va kiem » van kien
tin » tinh

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

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