Perhaps you should try some spelling variations:
cua triet » su triet, va triet
hieu van » hieu va, thien van, lieu va
hanh dai » hanh tai, hanh dao, vanh dai
cua viet » ca viet, hoa viet, cua vat
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
hieu ve » hieu va
thuc va » thuc vat, thuc dan, thuc day
va hanh » van hanh, va thanh, va danh
x hoi » xa hoi, o hoi, x ho

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 nang x hoi. ((hieu ve) OR (hieu van)) am thuc va hanh dai ((cua triet) OR (cua viet))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky nang x hoi. ((hieu ve) OR (hieu van)) am thuc va hanh dai ((cua triet) or (cua viet))~".
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang x hoi. ((hieu ve) OR (hieu van)) am thuc va hanh dai ((cua triet) or (cua viet))*.