Perhaps you should try some spelling variations:
trinh thong » trinh thuong, trinh tong, trinh khong
trinh trong » trinh truong, tranh trong, trinh trung
tinh quan » tinh quang, trinh quan, tin quan
hieu suat » hieu luat, hieu qua
van hieu » cao hieu
xuan van » quan van, xuan can, xuan tan
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 thong) OR (trinh trong)) 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 thong) OR (trinh trong)) 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 thong) OR (trinh trong)) xuan van kien hoa ))".
• Adding a wildcard symbol may retrieve word variants: (( tinh quan luan van hieu suat ) or ( ((trinh thong) OR (trinh trong)) xuan van kien hoa ))*.