Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
van hanh » van thanh, ban hanh, van anh
cham duc » pham duc, pham duy, phan duc
hanh dai » hanh tai, hanh dao, vanh dai
su sach » so sach, vu sach
sach tu » sach thu, cach tu, sach ty
tu nang » tru nang, tu nong, tu nano
hieu ve » hieu va, hieu van
x hoi » xa hoi, o hoi, 5 hoi

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sach tu nang ((x hoi) or (x ho)). hieu ve ((cham duc) OR (cham soc)) van hanh dai cua triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach tu nang ((x hoi) OR (x ho)). hieu ve ((cham duc) OR (cham soc)) van hanh dai cua triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach tu nang ((x hoi) or (x ho)). hieu ve ((cham duc) OR (cham soc)) van hanh dai cua triet".
• Adding a wildcard symbol may retrieve word variants: su sach tu nang ((x hoi) or (x ho)). hieu ve ((cham duc) OR (cham soc)) van hanh dai cua triet*.