Perhaps you should try some spelling variations:
van tham » van thanh, van tuan, van chat
dang xay » dang van, van xay
cua tre » cua te, cuu tre, cua triet
va hanh » van hanh, va thanh, va danh
va tham » va cham, va thanh, va thuat
lang xa » lang ha, lang van
soc va » hoc va, loc va, doc va
vi cua » vai cua, di cua
te cac » tu cac, ve cac, te cao

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 tham) OR (van tham)) soc va 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 tham) OR (van tham)) soc va hanh vi cua tre.
• 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) OR (van tham)) soc va hanh vi cua tre".
• Adding a wildcard symbol may retrieve word variants: te cac ky ((lang xa) or (dang xay)) hoi. hieu ((va tham) OR (van tham)) soc va hanh vi cua tre*.