Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van anh
su sach » so sach, vu sach
sach ty » sach y, sach tu, sach thu
xang xa » lang xa, mang xa, ang xa
hieu vu » hieu su, dieu vu, hieu qua
hieu ve » hieu van
hieu va » lieu va, hieu qua
soc van » hoc van, oc van, sac van
cua tre » cua te, cuu tre, cua triet
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: su sach ty xang xa hoi. ((((hieu vu) OR (hieu ve))) or (hieu va)) cham soc van hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ty xang xa hoi. ((((hieu vu) OR (hieu ve))) OR (hieu va)) cham soc van hanh vi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ty xang xa hoi. ((((hieu vu) OR (hieu ve))) or (hieu va)) cham soc van hanh vi cua tre".
• Adding a wildcard symbol may retrieve word variants: su sach ty xang xa hoi. ((((hieu vu) OR (hieu ve))) or (hieu va)) cham soc van hanh vi cua tre*.