Perhaps you should try some spelling variations:
tu sach » thu sach, su sach, te sach
luc van » luoc van, luu van, duc van
xuc van » duc van, xuc ban, thuc van
hieu va » lieu va, hieu qua
ty hang » ly hang, ty xang, thi hang
ty nang » ky nang, ty xang, ly nang
cua tre » cua te, cuu tre, cua triet
va cao » va cac, va co, va dao
vi cua » vai cua, di cua

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 ((ty nang) OR (ty hang)) xa hoi. hieu va cao ((xuc van) or (luc van)) hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ((ty nang) OR (ty hang)) xa hoi. hieu va cao ((xuc van) OR (luc van)) hanh vi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ((ty nang) OR (ty hang)) xa hoi. hieu va cao ((xuc van) or (luc van)) hanh vi cua tre".
• Adding a wildcard symbol may retrieve word variants: tu sach ((ty nang) OR (ty hang)) xa hoi. hieu va cao ((xuc van) or (luc van)) hanh vi cua tre*.