Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
hanh dieu » han dieu, hinh dieu, hoang dieu
dieu cua » dieu tra
van hanh » van thanh, ban hanh, van anh
hieu van » hieu va, thien van, lieu va
sach ky » sach y, sach ty, sach kem
hieu ve » hieu va
nang o » nang co, nang ho, nang ro
cam tu » cam thu, nam tu, dam tu
tu van » tu va
sac ky » cac ky, sai ky
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: so ((sach ky) OR (sac ky)) nang o hoi. ((hieu ve) or (hieu van)) cam tu van hanh dieu cua triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so ((sach ky) OR (sac ky)) nang o hoi. ((hieu ve) OR (hieu van)) cam tu van hanh dieu cua triet*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so ((sach ky) OR (sac ky)) nang o hoi. ((hieu ve) or (hieu van)) cam tu van hanh dieu cua triet*".