Perhaps you should try some spelling variations:
quang thanh » quan thanh, hoang thanh, muong thanh
chieu sach » chinh sach, chiet tach, chieu sang
nhung cong » dung cong, thong cong, hang cong
doi chieu » doc hieu, doi chi, mot chieu
anh quang » anh xquang, anh quan, nhanh quang
dang cong » dung cong
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 thanh ((nhung cong) or (dang cong)) tap toan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doi chieu sach - anh quang thanh ((nhung cong) OR (dang cong)) tap toan cau.
• Adding a wildcard symbol may retrieve word variants: doi chieu sach - anh quang thanh ((nhung cong) or (dang cong)) tap toan cau*.