Perhaps you should try some spelling variations:
chieu chien » thien chien
hieu hien » bieu hien, dieu hien, dieu khien
chua tre » chua tri, cua tre, chua trieu
nang xa » nang x, lang xa, nang ma
sach ky » sac ky, sach y, sach ty
dinh va » dinh van, dinh ve, tinh va
va chua » vua chua, ca chua, va chu
tu sach » thu sach, su sach, te sach
lao va » cao va, bao va, dao 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 nang xa hoi. ((hieu hien) OR (chieu chien)) cac ((lao va) or (tao va)) dinh va chua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang xa hoi. ((hieu hien) OR (chieu chien)) cac ((lao va) OR (tao va)) dinh va chua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky nang xa hoi. ((hieu hien) OR (chieu chien)) cac ((lao va) or (tao va)) dinh va chua tre".
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang xa hoi. ((hieu hien) OR (chieu chien)) cac ((lao va) or (tao va)) dinh va chua tre*.