Perhaps you should try some spelling variations:
thuoc sach » hoc sach, nuoc sach, thuat sach
ban thanh » ban hang
thu sach » tu sach, thuat sach, thu hoach
ban hanh » ban hang
hai cua » thai cua, dai cua, hoi cua
cua tre » cua te, cuu tre, cua triet
cam qua » cau qua, cac qua, cay qua
hieu va » lieu va, hieu qua
lang xa » lang ha, dang xay, lang van
y lang » o lang, _ lang, tay lang
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: ((thu sach) or (thuoc sach)) y lang xa hoi. hieu va cam qua ((ban thanh) OR (ban hanh)) hai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((thu sach) OR (thuoc sach)) y lang xa hoi. hieu va cam qua ((ban thanh) OR (ban hanh)) hai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((thu sach) or (thuoc sach)) y lang xa hoi. hieu va cam qua ((ban thanh) OR (ban hanh)) hai cua tre".
• Adding a wildcard symbol may retrieve word variants: ((thu sach) or (thuoc sach)) y lang xa hoi. hieu va cam qua ((ban thanh) OR (ban hanh)) hai cua tre*.