Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
vat cua » mat cua, bat cua, dat cua
van vat » van chat, nhan vat
cac dac » cac dan, cac dai, cac bac
sach ky » sac ky, sach y, sach ty
hieu va » lieu va, hieu qua
lang xa » dang xay, lang van
lang ha » long ha
cua tre » cua te, cuu tre, cua triet
da van » dao van, dam van, va van

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 ky ((lang xa) OR (lang ha)) hoi. hieu va ((cac dac) or (cac bai)) da van vat cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ky ((lang xa) OR (lang ha)) hoi. hieu va ((cac dac) OR (cac bai)) da van vat cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach ky ((lang xa) OR (lang ha)) hoi. hieu va ((cac dac) or (cac bai)) da van vat cua tre".
• Adding a wildcard symbol may retrieve word variants: thu sach ky ((lang xa) OR (lang ha)) hoi. hieu va ((cac dac) or (cac bai)) da van vat cua tre*.