Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van anh
tham soc » cham soc, tham nuoc, thai son
cua tre » cua te, cuu tre, cua triet
soc van » hoc van, oc van, sac van
hieu va » lieu va
lang xa » lang ha, dang xay, lang van
ky lang » ky nang, ky dang, ky tang
te san » te ban, ke san, tu san
vi cua » vai cua, di cua
te sac » te sach, te cac

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((te sac) OR (te san)) ky lang xa hoi. ((hieu va) or (hieu qua)) tham soc van hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((te sac) OR (te san)) ky lang xa hoi. ((hieu va) OR (hieu qua)) tham soc van hanh vi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((te sac) OR (te san)) ky lang xa hoi. ((hieu va) or (hieu qua)) tham soc van hanh vi cua tre".
• Adding a wildcard symbol may retrieve word variants: ((te sac) OR (te san)) ky lang xa hoi. ((hieu va) or (hieu qua)) tham soc van hanh vi cua tre*.