Perhaps you should try some spelling variations:
dang xay » dang van, van xay
tham hoc » thai hoc, tham hoa, than hoc
va hanh » van hanh, va thanh, va danh
hieu va » lieu va
cua tre » cua te, cuu tre, cua triet
lang xa » lang ha, lang van
sac ky » cac ky, sai ky
vi cua » vai cua, di cua
te sac » te sach, te cac, te san

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 ky ((lang xa) or (dang xay)) hoi. ((hieu va) or (hieu qua)) tham hoc va hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sac ky ((lang xa) OR (dang xay)) hoi. ((hieu va) OR (hieu qua)) tham hoc va hanh vi cua tre.
• Adding a wildcard symbol may retrieve word variants: te sac ky ((lang xa) or (dang xay)) hoi. ((hieu va) or (hieu qua)) tham hoc va hanh vi cua tre*.