Perhaps you should try some spelling variations:
ban thanh » ban hanh, ban hang
hieu van » hieu va, thien van, lieu va
duc ban » duc tan, duc van, dua ban
lai cua » dai cua, hai cua, lai chau
vai cua » dai cua, hai cua, bai cua
tu sach » thu sach, su sach, te sach
cao duc » dao duc, cao suc, giao duc
ky danh » ky anh
ky dang » ky nang
van cao » van dao, van bao, van hao

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach ((ky dang) OR (ky danh)) xa hoi. hieu van cao duc ban thanh ((vai cua) or (lai cua)) triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ((ky dang) OR (ky danh)) xa hoi. hieu van cao duc ban thanh ((vai cua) OR (lai cua)) triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ((ky dang) OR (ky danh)) xa hoi. hieu van cao duc ban thanh ((vai cua) or (lai cua)) triet".
• Adding a wildcard symbol may retrieve word variants: tu sach ((ky dang) OR (ky danh)) xa hoi. hieu van cao duc ban thanh ((vai cua) or (lai cua)) triet*.