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

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 tuc xa ((tinh vai) OR (tinh va)) 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 tuc xa ((tinh vai) OR (tinh va)) cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sach lo hang ((va hoi) or (va hoc)). hieu va cam tuc xa ((tinh vai) OR (tinh va)) cua tre".
• Adding a wildcard symbol may retrieve word variants: so sach lo hang ((va hoi) or (va hoc)). hieu va cam tuc xa ((tinh vai) OR (tinh va)) cua tre*.