Perhaps you should try some spelling variations:
luc van » luoc van, luu van, duc van
cac luc » cau luc, coc luc, cac nuoc
sach ky » sac ky, sach y, sach kem
qua cac » cua cac
nang xa » nang x, lang xa, nang ma
sach ty » sach y, sach tu, sach thu
cua tre » cua te, cuu tre, cua triet
anh va » hanh va
anh ve » hanh ve, anh viet, thanh ve

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 qua cac luc van ((anh va) or (anh ve)) 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 qua cac luc van ((anh va) OR (anh ve)) 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 qua cac luc van ((anh va) or (anh ve)) cua tre".
• Adding a wildcard symbol may retrieve word variants: tu ((sach ky) OR (sach ty)) nang xa hoi. hieu qua cac luc van ((anh va) or (anh ve)) cua tre*.