Perhaps you should try some spelling variations:
lang van » tang van, hoang van, giang van
dang van » hoang van, hang va
vat dung » van dung, va dung, viet dung
cua tre » cua te, cuu tre, cua triet
tai cua » thai cua, tai cuc, tri cua
tuc vat » thuc vat, tuc va, tuc hat
tu sai » tu bai, tu san, tu cai
va cao » va cac, va co, va dao
sai ky » sac ky
va cai » va cac, va bai, va dai

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: tu sai ky ((lang van) OR (dang van)) hoc. hieu ((va cai) or (va cao)) tuc vat dung tai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sai ky ((lang van) OR (dang van)) hoc. hieu ((va cai) OR (va cao)) tuc vat dung tai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sai ky ((lang van) OR (dang van)) hoc. hieu ((va cai) or (va cao)) tuc vat dung tai cua tre".
• Adding a wildcard symbol may retrieve word variants: tu sai ky ((lang van) OR (dang van)) hoc. hieu ((va cai) or (va cao)) tuc vat dung tai cua tre*.