Perhaps you should try some spelling variations:
trinh chuan » trinh han, trinh quan, trinh luan
chuan luan » chuyen luan, chuan doan, quan luan
tinh dung » trinh dung, tin dung, tinh quang
dung land » dung luan, dung lam, dung san
hieu suat » hieu luat, hieu qua
van chien » van hien, van tien
land van » lang van, lan van, luan van
van hieu » cao hieu
van kien » van tien, van 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 dung land van hieu suat ) or ( trinh chuan luan ((van kien) OR (van chien)) soat ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( tinh dung land van hieu suat ) OR ( trinh chuan luan ((van kien) OR (van chien)) soat ))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( tinh dung land van hieu suat ) or ( trinh chuan luan ((van kien) OR (van chien)) soat ))*".