Perhaps you should try some spelling variations:
va triet » va thiet, va trien, ve triet
van hang » van khang, van hoang, van thang
chat duc » chat xuc, chat doc, chet duoc
hieu van » thien van, lieu va, hieu ve
ty hang » ly hang, ty xang, thi hang
hieu va » lieu va, hieu qua
duc van » duc va, duc tan, duc manh
ty nang » ky nang, ty xang, ly nang
so sach » so sanh, bo sach, co sach
x hoi » xa hoi, o hoi, x ho
va va » va van, va vua, va vai

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

• Performing a fuzzy search may retrieve terms with similar spellings: so sach ((ty nang) OR (ty hang)) x hoi. ((hieu van) or (hieu va)) chat duc van hang va va triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach ((ty nang) OR (ty hang)) x hoi. ((hieu van) OR (hieu va)) chat duc van hang va va triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sach ((ty nang) OR (ty hang)) x hoi. ((hieu van) or (hieu va)) chat duc van hang va va triet".
• Adding a wildcard symbol may retrieve word variants: so sach ((ty nang) OR (ty hang)) x hoi. ((hieu van) or (hieu va)) chat duc van hang va va triet*.