Perhaps you should try some spelling variations:
hoc sach » hoc sinh, hoc cac, hoc anh
cham duc » pham duc, cham soc, pham duy
toan tai » toan tap, doanh tai, toan ban
tu sach » thu sach, su sach, te sach
nang xa » nang x, lang xa, nang ma
va cham » va chat, va tham
va toan » van toan, bai toan, tap toan
tai cua » thai cua, tai cuc, tri cua
cua tre » cua te, cuu tre, cua triet

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 (hoc sach)) ky nang xa hoi. lieu va cham duc va toan tai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (hoc sach)) ky nang xa hoi. lieu va cham duc va toan tai cua tre.
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (hoc sach)) ky nang xa hoi. lieu va cham duc va toan tai cua tre*.