Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
thien van » thi van
doc sach » hoc sach, toc sach, nuoc sach
ban hanh » ban hang
nuoc ban » nuoc san, quoc ban, buoc ban
hieu van » hieu va, lieu va, hieu ve
cac nuoc » cap nuoc, hoc nuoc, dat nuoc
hanh di » hanh vi, hanh de, hang di
te sach » toc sach
di cua » dai cua, doi cua, de cua
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) OR (thien van)) cac nuoc ban hanh di cua triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((te sach) OR (doc sach)) ky nang x hoi. ((hieu van) OR (thien van)) cac nuoc ban hanh di cua triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((te sach) or (doc sach)) ky nang x hoi. ((hieu van) OR (thien van)) cac nuoc ban hanh di cua triet".
• Adding a wildcard symbol may retrieve word variants: ((te sach) or (doc sach)) ky nang x hoi. ((hieu van) OR (thien van)) cac nuoc ban hanh di cua triet*.