Perhaps you should try some spelling variations:
dang xay » dang van, van xay
tham hoc » thai hoc, tham hoa, than hoc
lang xa » lang ha, lang van
hieu va » lieu va, hieu qua
va tham » van tham, va cham, va thanh
va hanh » van hanh, va thanh, va danh
cua tre » cuu tre, cua triet, dua tren
te cac » tu cac, ve cac, te cao
cua te » cua tu

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