Perhaps you should try some spelling variations:
so tang » son tang, so trang, do tang
tang ky » dang ky, trong ky, tang khu
va danh » va dinh, va dan, dia danh
va hanh » van hanh, va thanh, ban hanh
cua tre » cua te, cuu tre, cua triet
cac duc » cao duc, cac dac, cac nuoc
hieu ve » hieu va, hieu van
lang xa » lang ha, dang xay, lang van
ky lang » ky nang, ky dang, ky tang
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: so tang ky lang xa hoi. hieu ve ((cac duc) or (cac du)) ((va hanh) OR (va danh)) vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so tang ky lang xa hoi. hieu ve ((cac duc) OR (cac du)) ((va hanh) OR (va danh)) vi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so tang ky lang xa hoi. hieu ve ((cac duc) or (cac du)) ((va hanh) OR (va danh)) vi cua tre".
• Adding a wildcard symbol may retrieve word variants: so tang ky lang xa hoi. hieu ve ((cac duc) or (cac du)) ((va hanh) OR (va danh)) vi cua tre*.