Perhaps you should try some spelling variations:
thu sach » thuat sach, thuoc sach, thu hoach
tinh hoi » trinh hoi, tinh hoc, tinh hai
tu sach » su sach, te sach, tu cach
hoi cua » hoi chuc
va pham » van pham, va phat, va phap
hieu va » lieu va, hieu qua
hang xa » hoang xa, hang va, hang ca
tu hang » thu hang, tu hanh, tu hung
cua tre » cua te, cuu tre, cua triet
duy va » duy vat, duy van, duy v

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) or (thu sach)) tu hang xa hoi. hieu va pham ((duy va) OR (day va)) tinh hoi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (thu sach)) tu hang xa hoi. hieu va pham ((duy va) OR (day va)) tinh hoi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) or (thu sach)) tu hang xa hoi. hieu va pham ((duy va) OR (day va)) tinh hoi cua tre".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (thu sach)) tu hang xa hoi. hieu va pham ((duy va) OR (day va)) tinh hoi cua tre*.