Perhaps you should try some spelling variations:
va thanh » gia thanh, ban thanh, va tinh
cua tre » cua te, cuu tre, cua triet
va hanh » van hanh, va danh, ban hanh
lang xa » lang ha, dang xay, lang van
hieu va » lieu va, hieu qua
ky lang » ky nang, ky dang, ky tang
vi cua » vai cua, di cua
te cac » tu cac, ve cac, te cao
ham so » nam so

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: te cac ky lang xa hoi. hieu va ((ham so) OR (cham soc)) ((va hanh) OR (va thanh)) vi cua tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te cac ky lang xa hoi. hieu va ((ham so) or (cham soc)) ((va hanh) OR (va thanh)) vi cua tre~".
• Adding a wildcard symbol may retrieve word variants: te cac ky lang xa hoi. hieu va ((ham so) or (cham soc)) ((va hanh) OR (va thanh)) vi cua tre*.