Perhaps you should try some spelling variations:
tu sach » thu sach, su sach, te sach
sach ty » sach y, sach tu, sach thu
ty nang » ky nang, ty xang, ty hang
nang xa » nang x, lang xa, nang ma
hieu va » lieu va, hieu qua
cac duc » cac du, cao duc, cac nuoc
cac dac » cac dan, cac dai, cac bac
cua tre » cua te, cuu tre, cua triet

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 ty nang xa hoi. hieu va ((cac duc) OR (cac dac)) va ((danh cho) OR (dan ca)) cua tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ty nang xa hoi. hieu va ((cac duc) OR (cac dac)) va ((danh cho) or (dan ca)) cua tre~".
• Adding a wildcard symbol may retrieve word variants: tu sach ty nang xa hoi. hieu va ((cac duc) OR (cac dac)) va ((danh cho) or (dan ca)) cua tre*.