Perhaps you should try some spelling variations:
dang xay » dang van, van xay
thai son » thai den, thai do, thai hoc
van hanh » van thanh, ban hanh, van anh
lang xa » lang ha, lang van
hieu va » lieu va, hieu qua
va thai » van thai, va tai, va tham
son van » song van, san van, son va
cua tre » cua te, cuu tre, cua triet
te cac » tu cac, ve cac, te cao
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: te cac ky ((lang xa) or (dang xay)) hoi. hieu va thai son van hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te cac ky ((lang xa) OR (dang xay)) hoi. hieu va thai son van hanh vi cua tre.
• Adding a wildcard symbol may retrieve word variants: te cac ky ((lang xa) or (dang xay)) hoi. hieu va thai son van hanh vi cua tre*.