Perhaps you should try some spelling variations:
thien hach » thien thanh, hien hanh
hieu thien » hieu hien, chieu chien, dieu khien
cua triet » cua viet, su triet, va triet
sach ky » sac ky, sach y, sach ty
hach tu » hanh tu, cach tu, sach tu
su sach » so sach, vu sach
nang o » nang co, nang ho, nang ro
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 thien hach tu ((((ca dan) or (ca dao))) 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 thien hach tu ((((ca dan) OR (ca dao))) OR (cac dan)) vi cua triet.
• Adding a wildcard symbol may retrieve word variants: su sach ky nang o hoi. hieu thien hach tu ((((ca dan) or (ca dao))) or (cac dan)) vi cua triet*.