Perhaps you should try some spelling variations:
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
nang xa » nang x, lang xa, nang ma
qua cac » cua cac
cac luc » cau luc, coc luc, cac nuoc
luc van » luoc van, luu van, duc van
hanh ve » hanh vi, hanh va, hanh kem
cua tre » cua te, cuu tre, cua triet
anh vi » hanh vi, anh va, anh vu
anh ve » anh va, 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 nang xa hoi. hieu qua cac luc van ((anh vi) or (((anh ve) OR (hanh ve)))) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang xa hoi. hieu qua cac luc van ((anh vi) OR (((anh ve) OR (hanh ve)))) cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky nang xa hoi. hieu qua cac luc van ((anh vi) or (((anh ve) OR (hanh ve)))) cua tre".
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang xa hoi. hieu qua cac luc van ((anh vi) or (((anh ve) OR (hanh ve)))) cua tre*.