Perhaps you should try some spelling variations:
ban hanh » ban hang
cham hoc » cham soc, chat hoc, cham hoi
tu sach » thu sach, su sach, te sach
sach ty » sach y, sach tu, sach thu
cua tre » cua te, cua triet, dua tren
hoc ban » hoc bang, hoc dan, hoc bai
hieu va » lieu va, hieu qua
hieu vu » hieu ve, hieu su, dieu vu
xang xa » lang xa, mang xa, ang xa
cuu tre » cau tren, cau treo

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 xang xa hoi. ((hieu vu) or (hieu va)) cham hoc ban hanh vi ((cua tre) or (cuu tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ty xang xa hoi. ((hieu vu) OR (hieu va)) cham hoc ban hanh vi ((cua tre) OR (cuu tre)).
• Adding a wildcard symbol may retrieve word variants: tu sach ty xang xa hoi. ((hieu vu) or (hieu va)) cham hoc ban hanh vi ((cua tre) or (cuu tre))*.