Perhaps you should try some spelling variations:
trinh chuan » trinh han, trinh quan, trinh luan
chuan luan » chuyen luan, chuan doan, quan luan
hieu suat » hieu luat, hieu qua
dung dang » dung dong, dung danh, dung dung
kiem soat » kiem toan
dung dan » dung dat, dung san, tung dan
van hieu » cao hieu
van kiem » va kiem, van kien, van hien

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: (( trinh ((dung dang) OR (dung dan)) van hieu suat ) OR ( trinh chuan luan van kiem soat ))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( trinh ((dung dang) OR (dung dan)) van hieu suat ) or ( trinh chuan luan van kiem soat ))~".
• Adding a wildcard symbol may retrieve word variants: (( trinh ((dung dang) OR (dung dan)) van hieu suat ) or ( trinh chuan luan van kiem soat ))*.