Perhaps you should try some spelling variations:
vanh dai » van dai, vanh tai, lanh dao
thuc va » thuc dan, thuc day
va nham » va cham, va tham, va nha
hieu va » lieu va, hieu qua
sach ky » sach y, sach ty, sach kem
dang xa » dang xay, lang xa, dang ha
cua tre » cua te, cuu tre, cua triet
sac ky » cac ky, sai ky

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu ((sach ky) or (sac ky)) dang xa hoi. hieu va nham ((thuc va) OR (thuc vat)) vanh dai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach ky) OR (sac ky)) dang xa hoi. hieu va nham ((thuc va) OR (thuc vat)) vanh dai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu ((sach ky) or (sac ky)) dang xa hoi. hieu va nham ((thuc va) OR (thuc vat)) vanh dai cua tre".
• Adding a wildcard symbol may retrieve word variants: tu ((sach ky) or (sac ky)) dang xa hoi. hieu va nham ((thuc va) OR (thuc vat)) vanh dai cua tre*.