Perhaps you should try some spelling variations:
thuong quang » thong quang, truong quang, phuong quang
thuong quan » thong quan, truong quan, tuong quan
hieu soat » hieu suat, hieu hoat, hieu luat
luan bien » luan lien, xuan bien, luong bien
bien soan » bien so
van hieu » cao hieu
tin » tinh

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( tin dung luan van hieu soat ) or ( ton ((thuong quan) OR (thuong quang)) luan bien soan ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( tin dung luan van hieu soat ) OR ( ton ((thuong quan) OR (thuong quang)) luan bien soan )).
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( tin dung luan van hieu soat ) or ( ton ((thuong quan) OR (thuong quang)) luan bien soan ))".
• Adding a wildcard symbol may retrieve word variants: (( tin dung luan van hieu soat ) or ( ton ((thuong quan) OR (thuong quang)) luan bien soan ))*.