Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
sach ty » sach y, sach tu, sach thu
tang ma » mang may, tang van
lang xa » lang ha, dang xay, lang van
qua cam » qua cham, qua cac, qua ca
vai cua » dai cua, hai cua, lai 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: thu sach ty ((tang ma) or (lang xa)) hoi. hieu qua cam xuc ((va tinh) OR (may tinh)) vai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ty ((tang ma) OR (lang xa)) hoi. hieu qua cam xuc ((va tinh) OR (may tinh)) vai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach ty ((tang ma) or (lang xa)) hoi. hieu qua cam xuc ((va tinh) OR (may tinh)) vai cua tre".
• Adding a wildcard symbol may retrieve word variants: thu sach ty ((tang ma) or (lang xa)) hoi. hieu qua cam xuc ((va tinh) OR (may tinh)) vai cua tre*.