Perhaps you should try some spelling variations:
hieu van » thien van, lieu va, hieu ve
van hanh » van thanh, ban hanh, van anh
va triet » va thiet, va trien, ve triet
su triet » su viet, su tien, ve triet
hieu va » lieu va, hieu qua
cac tuc » cac toc, cac tu, cac tac
tuc van » thuc van, truc van, tuc va
su sai » su tai, su hai, su dai
sai ky » sac ky
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 sai ky nang o hoi. ((hieu van) OR (hieu va)) cac tuc van hanh vi ((va triet) or (su triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sai ky nang o hoi. ((hieu van) OR (hieu va)) cac tuc van hanh vi ((va triet) OR (su triet))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sai ky nang o hoi. ((hieu van) OR (hieu va)) cac tuc van hanh vi ((va triet) or (su triet))*".