Perhaps you should try some spelling variations:
ban thanh » ban hanh, ban hang
thanh doi » thanh loi, thanh moi, thanh do
cac nuoc » cap nuoc, hoc nuoc, dat nuoc
nuoc ban » nuoc san, quoc ban, buoc ban
doc sach » hoc sach, toc sach, nuoc sach
su triet » su viet, ve triet
hieu van » hieu va, thien van, lieu va
te sach » toc sach
van cac » van hac, van cau, van bac
su tien » su kien, su hien, tu tieng
x hoi » xa hoi, o hoi, x ho

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((te sach) or (doc sach)) ky nang x hoi. hieu van cac nuoc ban thanh doi ((su triet) OR (su tien))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((te sach) OR (doc sach)) ky nang x hoi. hieu van cac nuoc ban thanh doi ((su triet) OR (su tien)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((te sach) or (doc sach)) ky nang x hoi. hieu van cac nuoc ban thanh doi ((su triet) OR (su tien))".
• Adding a wildcard symbol may retrieve word variants: ((te sach) or (doc sach)) ky nang x hoi. hieu van cac nuoc ban thanh doi ((su triet) OR (su tien))*.