Perhaps you should try some spelling variations:
trinh chuan » trinh han, trinh quan, trinh luan
tinh dung » trinh dung, tin dung, tinh quang
hieu suat » hieu luat, hieu qua
kien soat » kiem soat, bien soan, kien hoa
dung san » dong san, dung sai, dung luan
van hieu » cao hieu
doan van » doan va, hoang van, tran van
san van » tan van, tran van, dang van
luan » quan, lan

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