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
cuu tre » cua tre, cau tren, cau treo
van cac » van hac, van cau, van bac
cac luc » cau luc, coc luc, cac nuoc
ky lang » ky nang, ky dang, ky tang
sac ky » cac ky, sai ky
va cuu » va cau, va chu, va huu
su sac » su sach, su cac, su xac

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sac ky lang ((van hoc) OR (van hoa)). hieu van cac luc ((va thanh) or (ban thanh)) va cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sac ky lang ((van hoc) OR (van hoa)). hieu van cac luc ((va thanh) OR (ban thanh)) va cuu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sac ky lang ((van hoc) OR (van hoa)). hieu van cac luc ((va thanh) or (ban thanh)) va cuu tre".
• Adding a wildcard symbol may retrieve word variants: su sac ky lang ((van hoc) OR (van hoa)). hieu van cac luc ((va thanh) or (ban thanh)) va cuu tre*.