Perhaps you should try some spelling variations:
vien dai » hien dai
va hanh » van hanh, va thanh, va danh
hai hau » hai chau, hai hai, lai chau
dai hau » dai han, dai hai, dai huu
ve cac » va cac, vien cac
sac ky » cac ky, sai ky
xuc va » duc va, tuc va, luc va
nang o » nang co, nang ho, nang ro
su sac » su sach, su cac, su xac
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 sac ky nang o hoi. hieu ((ve cac) or (vien dai)) xuc va hanh ((hai hau) OR (dai hau)) theo~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sac ky nang o hoi. hieu ((ve cac) OR (vien dai)) xuc va hanh ((hai hau) OR (dai hau)) theo*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sac ky nang o hoi. hieu ((ve cac) or (vien dai)) xuc va hanh ((hai hau) OR (dai hau)) theo*".