Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
van hanh » van thanh, van anh, van ban
ban hanh » ban hang
nang xa » nang x, lang xa, nang ma
cac loc » cac toc, cac hoc, cac nuoc
cac lop » cac hop, cac loai
cua tre » cua te, cuu tre, cua triet
tu can » tu ban, tu cac, thu canh
can ky » van ky, dan ky, ban ky
vi cua » vai cua, di cua

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

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