Perhaps you should try some spelling variations:
xanh hanh » danh thanh, van hanh, dang hanh
cua triet » cua viet, su triet, va triet
dang xay » dang van, van xay
ban hanh » ban hang
cao duc » dao duc, cao suc, giao duc
vai cua » dai cua, hai cua, lai cua
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
hieu ve » hieu va, hieu van
ve cao » va cao, ve bao, ve cac

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

• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky ((dang xay) OR (nang x)) hoi. hieu ve cao duc ((xanh hanh) OR (ban hanh)) vai cua triet~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky ((dang xay) or (nang x)) hoi. hieu ve cao duc ((xanh hanh) OR (ban hanh)) vai cua triet~".
• Adding a wildcard symbol may retrieve word variants: tu sach ky ((dang xay) or (nang x)) hoi. hieu ve cao duc ((xanh hanh) OR (ban hanh)) vai cua triet*.