Perhaps you should try some spelling variations:
toc sach » doc sach, thuoc sach, nuoc sach
hoc sach » hoc sinh, hoc cac, hoc anh
hanh hai » thanh hai, nhanh hai, hang hai
ban hanh » ban hang
hai cua » thai cua, dai cua, hoi cua
duc ban » duc tan, duc van, dua ban
cac duc » cac du, cao duc, cac dac
mang xa » lang xa, mang may, dang xay
hieu va » lieu va, hieu qua
bang xa » lang xa, bang va, ang xa
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: ((toc sach) OR (hoc sach)) thu ((bang xa) or (mang xa)) hoi. hieu va cac duc ban hanh hai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((toc sach) OR (hoc sach)) thu ((bang xa) OR (mang xa)) hoi. hieu va cac duc ban hanh hai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((toc sach) OR (hoc sach)) thu ((bang xa) or (mang xa)) hoi. hieu va cac duc ban hanh hai cua tre".
• Adding a wildcard symbol may retrieve word variants: ((toc sach) OR (hoc sach)) thu ((bang xa) or (mang xa)) hoi. hieu va cac duc ban hanh hai cua tre*.