Perhaps you should try some spelling variations:
ban thanh » ban hanh, ban hang
va thanh » gia thanh, va tinh, le thanh
hieu van » hieu va, thien van, lieu va
vu sach » su sach, vu khach
cac tuc » cac toc, cac tu, cac tac
van cac » van hac, van cau, van bac
lang xa » lang ha, dang xay, lang van
ky lang » ky nang, ky dang, ky tang
cua tre » cua te, cuu tre, cua triet
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: ((vu sach) OR (vu bach)) ky lang xa hoi. hieu van cac tuc ((va thanh) or (ban thanh)) vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((vu sach) OR (vu bach)) ky lang xa hoi. hieu van cac tuc ((va thanh) OR (ban thanh)) vi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((vu sach) OR (vu bach)) ky lang xa hoi. hieu van cac tuc ((va thanh) or (ban thanh)) vi cua tre".
• Adding a wildcard symbol may retrieve word variants: ((vu sach) OR (vu bach)) ky lang xa hoi. hieu van cac tuc ((va thanh) or (ban thanh)) vi cua tre*.