Perhaps you should try some spelling variations:
tinh vai » tinh va, tinh hai, tinh bai
so sach » so sanh, bo sach, co sach
sach lo » sach dao, sach doi, sach hoi
lo hang » ly hang, le hang, cho hang
hieu va » lieu va, hieu qua
xa tinh » va tinh, ha tinh, ca tinh
vai cua » dai cua, hai cua, lai cua
cua tre » cua te, cuu tre, cua triet
va hoi » xa hoi, va hoa
va hoc » van hoc
va cam » va cham, va cac, va cao
cam te » cam tu, cam tien
te xa » te va

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

• Performing a fuzzy search may retrieve terms with similar spellings: so sach lo hang ((va hoi) or (va hoc)). hieu va cam te xa tinh vai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach lo hang ((va hoi) OR (va hoc)). hieu va cam te xa tinh vai cua tre.
• Adding a wildcard symbol may retrieve word variants: so sach lo hang ((va hoi) or (va hoc)). hieu va cam te xa tinh vai cua tre*.