Perhaps you should try some spelling variations:
cuong hieu » cong hieu, guong hieu, huong hieu
sach hoi » sach doi, sach moi, cach thoi
thuc dai » thuc day, thuc tai, thu dai
thuc dan » thuc hanh, hoc dan, thuc vat
hieu hoc » lieu hoc, hieu hoa, tieu hoc
hoc giai » hoc giao, hoc dai, so giai
tu sach » thu sach, su sach, te sach

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach hoi ((thuc dai) or (thuc dan)) cuong hieu hoc giai~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach hoi ((thuc dai) OR (thuc dan)) cuong hieu hoc giai.
• Adding a wildcard symbol may retrieve word variants: tu sach hoi ((thuc dai) or (thuc dan)) cuong hieu hoc giai*.