Perhaps you should try some spelling variations:
nam duoc » nam thuoc, da duoc, dat duoc
van hanh » van thanh, van anh, van ban
ban hanh » ban hang
thai cua » than cua, tai cuc, tri cua
ky dang » ky nang, ky danh
dang xa » dang xay, lang xa, dang ha
hieu ve » hieu va, hieu van
cua tre » cua te, cuu tre, cua triet
tai ky » thai ky, trai ky, sai ky

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu tai ky dang xa hoi. hieu ve ((nam duoc) or (pham duc)) ((van hanh) or (ban hanh)) thai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu tai ky dang xa hoi. hieu ve ((nam duoc) OR (pham duc)) ((van hanh) OR (ban hanh)) thai cua tre.
• Adding a wildcard symbol may retrieve word variants: tu tai ky dang xa hoi. hieu ve ((nam duoc) or (pham duc)) ((van hanh) or (ban hanh)) thai cua tre*.