Perhaps you should try some spelling variations:
hien bach » vien bach, thien hach, hien hanh
hieu hien » bieu hien, dieu hien, chieu chien
cua triet » cua viet, su triet, va triet
su sach » so sach, vu sach
sach ky » sac ky, sach y, sach ty
bach tu » bach thu, cach tu, bac tu
nang o » nang co, nang ho, nang ro
ca dan » ca dao
vi cua » vai cua, di cua
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 ky nang o hoi. hieu hien bach tu ((ca dan) or (cac dan)) vi cua triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky nang o hoi. hieu hien bach tu ((ca dan) OR (cac dan)) vi cua triet.
• Adding a wildcard symbol may retrieve word variants: su sach ky nang o hoi. hieu hien bach tu ((ca dan) or (cac dan)) vi cua triet*.