Perhaps you should try some spelling variations:
trung quang » truong quang, trung quan, thuong quang
trong quang » truong quang, thong quang, trong quan
doi chieu » doc hieu, doi chi, ho chieu
anh quang » anh xquang, anh quan, nhanh quang
cuong tap » luong tap, cong tac, luong tai
tap toan » tap doan, tap quan, bai toan
toan cau » toan cao, toan ban, toan tap

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((doi chieu) OR (mot chieu)) sach - anh quang ((trung quang) or (trong quang)) cuong tap toan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((doi chieu) OR (mot chieu)) sach - anh quang ((trung quang) OR (trong quang)) cuong tap toan cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((doi chieu) OR (mot chieu)) sach - anh quang ((trung quang) or (trong quang)) cuong tap toan cau".
• Adding a wildcard symbol may retrieve word variants: ((doi chieu) OR (mot chieu)) sach - anh quang ((trung quang) or (trong quang)) cuong tap toan cau*.