Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
cac nuoc » cap nuoc, hoc nuoc, dat nuoc
thanh de » hanh de, thanh ve, thanh do
doc sach » hoc sach, toc sach, nuoc sach
thanh di » thanh doi, thanh do, thanh dinh
nuoc ban » nuoc san, quoc ban, buoc ban
te sach » toc sach
hieu ve » hieu va, hieu van
nang o » nang co, nang ho, nang ro
ve cac » va cac, vien cac
o hoi » co hoi, o hoc, o hai

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 o hoi. hieu ve cac nuoc ban ((thanh di) OR (thanh de)) cua triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((te sach) OR (doc sach)) ky nang o hoi. hieu ve cac nuoc ban ((thanh di) OR (thanh de)) cua triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((te sach) or (doc sach)) ky nang o hoi. hieu ve cac nuoc ban ((thanh di) OR (thanh de)) cua triet".
• Adding a wildcard symbol may retrieve word variants: ((te sach) or (doc sach)) ky nang o hoi. hieu ve cac nuoc ban ((thanh di) OR (thanh de)) cua triet*.