Perhaps you should try some spelling variations:
va triet » va thiet, va trien, ve triet
danh vai » danh sai, danh va, doanh van
ban danh » ban doanh, ban hanh, ban dan
sach ty » sach y, sach tu, sach thu
cua tre » cua te, cuu tre, cua triet
tu sach » thu sach, su sach, te sach
hieu va » lieu va, hieu qua
hieu ve » hieu van
xang xa » lang xa, mang xa, ang xa
ca cua » co cua

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 ty xang xa hoi. ((hieu ve) OR (hieu va)) ca cua ban danh vai ((cua tre) or (va triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ty xang xa hoi. ((hieu ve) OR (hieu va)) ca cua ban danh vai ((cua tre) OR (va triet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ty xang xa hoi. ((hieu ve) OR (hieu va)) ca cua ban danh vai ((cua tre) or (va triet))".
• Adding a wildcard symbol may retrieve word variants: tu sach ty xang xa hoi. ((hieu ve) OR (hieu va)) ca cua ban danh vai ((cua tre) or (va triet))*.