Perhaps you should try some spelling variations:
quang tran » quang tuan, quang trung, quang thanh
chieu sach » chinh sach, chiet tach, chieu sang
tran nhung » tranh nhung, tran hung, tren nhung
nhung cong » dung cong, thong cong, hang cong
anh quang » anh xquang, anh quan, nhanh quang
tap toan » tap doan, tap quan
bai toan » bai tap
co sach » bo sach, cuon sach, hoc sach

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) or (co sach)) - anh quang tran nhung cong ((tap toan) or (bai toan)) cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doi ((chieu sach) OR (co sach)) - anh quang tran nhung cong ((tap toan) OR (bai toan)) cau.
• Adding a wildcard symbol may retrieve word variants: doi ((chieu sach) or (co sach)) - anh quang tran nhung cong ((tap toan) or (bai toan)) cau*.