Perhaps you should try some spelling variations:
hieu sau » hieu suat, tieu su, hieu va
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
nang xa » nang x, lang xa, nang ma
hieu vu » hieu va, hieu ve, dieu vu
hieu su » tieu su, hieu so, hieu suat
soc van » hoc van, oc van, sac van
minh va » tinh va, sinh va, sinh vat
cua tre » cua te, cuu tre, cua triet
va cua » va chua, via cua, ca cua

You may be able to get more results by adjusting your search query.

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