Perhaps you should try some spelling variations:
sach ky » sac ky, sach y, sach kem
sach ty » sach y, sach tu, sach thu
nang xa » nang x, lang xa, nang ma
hieu va » hieu qua
cac duc » cac du, cao duc, cac dac
dan vai » dan va, dan tai, dan vat
vai cua » dai cua, hai cua, lai cua
cua tre » cua te, cuu tre, cua triet
va dan » ca dan, va dao, va dau

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) or (sach ty)) nang xa hoi. ((hieu va) or (lieu va)) cac duc va dan vai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu ((sach ky) OR (sach ty)) nang xa hoi. ((hieu va) OR (lieu va)) cac duc va dan vai cua tre.
• Adding a wildcard symbol may retrieve word variants: thu ((sach ky) or (sach ty)) nang xa hoi. ((hieu va) or (lieu va)) cac duc va dan vai cua tre*.