Perhaps you should try some spelling variations:
vien cac » vien bach, vien dai, vien da
ban hanh » ban hang
van hanh » van thanh, van anh, van ban
vai cua » dai cua, hai cua, lai cua
cua tre » cua te, cuu tre, cua triet
nang xa » nang x, lang xa, nang ma
san ky » sang ky, van ky, dan ky
ve cac » va cac
tu san » thu san, tu ban, tu can

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

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