Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van anh
danh ky » hanh ky, dan ky, dang ky
cua tre » cuu tre, cua triet, dua tren
hieu ve » hieu va, hieu van
so danh » do danh, so sanh, so dan
lang xa » dang xay, lang van
lang ha » long ha
ve cac » va cac, vien cac
du van » duy van, duc van, tu van
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: so danh ky ((lang xa) OR (lang ha)) hoi. hieu ve cac du van hanh vi ((cua tre) OR (cua te))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so danh ky ((lang xa) or (lang ha)) hoi. hieu ve cac du van hanh vi ((cua tre) OR (cua te))~".
• Adding a wildcard symbol may retrieve word variants: so danh ky ((lang xa) or (lang ha)) hoi. hieu ve cac du van hanh vi ((cua tre) OR (cua te))*.