Perhaps you should try some spelling variations:
trong xuan » truong xuan, trong quan, trong tuan
thong xuan » thong quan, thong luan, thong quang
tinh quan » tinh quang, trinh quan, tin quan
hieu suat » hieu luat, hieu qua
van hieu » cao hieu
van kien » van tien, van hien, van chien
kien hoa » dien hoa, tien hoa, kien ha
luan » lan

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( tinh quan luan van hieu suat ) or ( trinh ((trong xuan) OR (thong xuan)) van kien hoa ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( tinh quan luan van hieu suat ) OR ( trinh ((trong xuan) OR (thong xuan)) van kien hoa )).
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( tinh quan luan van hieu suat ) or ( trinh ((trong xuan) OR (thong xuan)) van kien hoa ))".
• Adding a wildcard symbol may retrieve word variants: (( tinh quan luan van hieu suat ) or ( trinh ((trong xuan) OR (thong xuan)) van kien hoa ))*.