Perhaps you should try some spelling variations:
vanh dai » van dai, vanh tai, lanh dao
sach ky » sac ky, sach y, sach kem
hieu va » lieu va, hieu qua
nang xa » nang x, lang xa, nang ma
sach ty » sach y, sach tu, sach thu
cua tre » cua te, cuu tre, cua triet
va cam » va cham, va cac, va cao
tuc va » thuc va, truc va, duc va

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 (sach ty)) nang xa hoi. hieu va cam ((tuc va) or (tuc xa)) vanh dai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach ky) OR (sach ty)) nang xa hoi. hieu va cam ((tuc va) OR (tuc xa)) vanh dai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu ((sach ky) OR (sach ty)) nang xa hoi. hieu va cam ((tuc va) or (tuc xa)) vanh dai cua tre".
• Adding a wildcard symbol may retrieve word variants: tu ((sach ky) OR (sach ty)) nang xa hoi. hieu va cam ((tuc va) or (tuc xa)) vanh dai cua tre*.