Perhaps you should try some spelling variations:
chieu sach » chinh sach, chiet tach, chieu sang
doi chieu » doc hieu, doi chi, mot chieu
anh quang » anh xquang, anh quan, nhanh quang
tran hong » tran hoang, tran trong, tranh hang
cuong tap » luong tap, cong tac, luong tai
tran huu » tran duc
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 sach - anh quang ((tran huu) or (tran hong)) cuong tap toan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doi chieu sach - anh quang ((tran huu) OR (tran hong)) cuong tap toan cau.
• Adding a wildcard symbol may retrieve word variants: doi chieu sach - anh quang ((tran huu) or (tran hong)) cuong tap toan cau*.