Perhaps you should try some spelling variations:
su triet » su viet, su tien, ve triet
va triet » va thiet, va trien, ve triet
van hanh » van thanh, ban hanh, van anh
hieu van » hieu va, thien van, lieu va
van cac » van hac, van cau, van bac
cac tuc » cac toc, cac tu, cac tac
tuc van » thuc van, truc van, tuc va
nang o » nang co, nang ho, nang ro
su dai » sau dai, si dai, su tai
su sai » su tai, su hai, su mai
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) OR (su dai)) ky nang o hoi. hieu van 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) OR (su dai)) ky nang o hoi. hieu van 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) OR (su dai)) ky nang o hoi. hieu van cac tuc van hanh vi ((va triet) or (su triet))*".