Perhaps you should try some spelling variations:
cua triet » cua viet, va triet
su triet » su viet, su tien, ve triet
cham duc » pham duc, pham duy, phan duc
hanh dai » hanh tai, hanh dao, vanh dai
van hanh » van thanh, ban hanh, van anh
su sach » so sach, vu sach
sach tu » sach thu, cach tu, sach ty
hieu vu » hieu va, hieu ve, hieu su
tu nang » tru nang, tu nong, tu nano
nang o » nang co, nang ho, nang ro
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: su sach tu nang o hoi. hieu vu ((cham duc) OR (cham soc)) van hanh dai ((cua triet) or (su triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach tu nang o hoi. hieu vu ((cham duc) OR (cham soc)) van hanh dai ((cua triet) OR (su triet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach tu nang o hoi. hieu vu ((cham duc) OR (cham soc)) van hanh dai ((cua triet) or (su triet))".
• Adding a wildcard symbol may retrieve word variants: su sach tu nang o hoi. hieu vu ((cham duc) OR (cham soc)) van hanh dai ((cua triet) or (su triet))*.