Perhaps you should try some spelling variations:
vu khach » vu khanh, vu khac, vay khach
chua tre » chua tri, cua tre, chua trieu
xay hoi » xa hoi, tay hoi, cay phoi
hai loc » hau loc, khai luoc, hai long
hanh va » hanh vi
ky van » ly van, ky va
ty van » ly van, ta van
va hai » van hai, va chai, va khai
loc va » hoc va, luc va

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: vu khach ((ky van) or (ty van)) xay hoi. lieu va hai loc va ((hanh va) OR (hang va)) chua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu khach ((ky van) OR (ty van)) xay hoi. lieu va hai loc va ((hanh va) OR (hang va)) chua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "vu khach ((ky van) or (ty van)) xay hoi. lieu va hai loc va ((hanh va) OR (hang va)) chua tre".
• Adding a wildcard symbol may retrieve word variants: vu khach ((ky van) or (ty van)) xay hoi. lieu va hai loc va ((hanh va) OR (hang va)) chua tre*.