Perhaps you should try some spelling variations:
dang xay » dang van, van xay
hanh vai » hanh vi, hanh tai, hanh van
cua tre » cua te, cuu tre, cua triet
lang xa » lang ha, lang van
hanh va » hang va, hanh vi
hieu ve » hieu va, hieu van
cac loc » cac lop, cac toc, cac hoc
tu sac » tu sach, tu cac, tu san
loc va » hoc va, luc va
sac ky » cac ky, sai ky
ve cac » va cac, vien cac

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: tu sac ky ((lang xa) or (dang xay)) hoi. hieu ve cac loc va ((hanh vai) OR (hanh va)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sac ky ((lang xa) OR (dang xay)) hoi. hieu ve cac loc va ((hanh vai) OR (hanh va)) cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sac ky ((lang xa) or (dang xay)) hoi. hieu ve cac loc va ((hanh vai) OR (hanh va)) cua tre".
• Adding a wildcard symbol may retrieve word variants: tu sac ky ((lang xa) or (dang xay)) hoi. hieu ve cac loc va ((hanh vai) OR (hanh va)) cua tre*.