Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van anh
dieu cua » dieu tra
cac nuoc » cap nuoc, hoc nuoc, dat nuoc
san hanh » san thanh, ban hanh, dan hanh
cua tre » cua te, cuu tre, cua triet
ky lang » ky nang, ky dang, ky tang
van hoi » van hoa, van hoc, van loi
van hoe » van hoa, van hoc, van hieu
hieu ve » hieu va, hieu van
te ban » te bao
ban ky » van ky, dan 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: te ban ky lang ((van hoi) or (van hoe)). hieu ve cac nuoc ((san hanh) OR (van hanh)) dieu cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te ban ky lang ((van hoi) OR (van hoe)). hieu ve cac nuoc ((san hanh) OR (van hanh)) dieu cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te ban ky lang ((van hoi) or (van hoe)). hieu ve cac nuoc ((san hanh) OR (van hanh)) dieu cua tre".
• Adding a wildcard symbol may retrieve word variants: te ban ky lang ((van hoi) or (van hoe)). hieu ve cac nuoc ((san hanh) OR (van hanh)) dieu cua tre*.