Perhaps you should try some spelling variations:
vien cac » vien bach, vien dai, vien da
so sanh » do sanh
va hanh » van hanh, va thanh, va danh
sanh ky » hanh ky, sang ky, nganh ky
lang ha » long ha
lang xa » dang xay, lang van
cua tre » cua te, cuu tre, cua triet
ve cac » va cac
vi cua » vai cua, di cua
du va » dau va, tu va, su va

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 sanh ky ((lang xa) OR (lang ha)) hoi. hieu ((ve cac) OR (vien cac)) du va hanh vi cua tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sanh ky ((lang xa) or (lang ha)) hoi. hieu ((ve cac) OR (vien cac)) du va hanh vi cua tre~".
• Adding a wildcard symbol may retrieve word variants: so sanh ky ((lang xa) or (lang ha)) hoi. hieu ((ve cac) OR (vien cac)) du va hanh vi cua tre*.