Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van anh
tu cach » tu cac
va danh » va dinh, va dan, va hanh
cach tu » cach thuc
hieu ve » hieu va, hieu van
cua tre » cua te, cuu tre, cua triet
nang xa » lang xa, nang ma, mang xa
va cua » va chua, via cua, ca cua
ve cac » va cac, vien cac
cac o » cac co, cac bo, cac ho

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu cach tu ((nang xa) or (nang x)) hoi. hieu ve cac o ((van hanh) or (va danh)) va cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu cach tu ((nang xa) OR (nang x)) hoi. hieu ve cac o ((van hanh) OR (va danh)) va cua tre.
• Adding a wildcard symbol may retrieve word variants: tu cach tu ((nang xa) or (nang x)) hoi. hieu ve cac o ((van hanh) or (va danh)) va cua tre*.