Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
cac cong » cua cong
cong van » cong vang, cong san, song van
van hanh » van thanh, ban hanh, van anh
hanh hai » thanh hai, nhanh hai, hang hai
tu sach » thu sach, te sach, tu cach
su sach » so sach, vu sach
hieu ve » hieu va, hieu van
hai cua » thai cua, dai cua, hoi cua
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: ((tu sach) or (su sach)) ky nang o hoi. hieu ve cac cong van hanh hai cua triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (su sach)) ky nang o hoi. hieu ve cac cong van hanh hai cua triet.
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (su sach)) ky nang o hoi. hieu ve cac cong van hanh hai cua triet*.