Perhaps you should try some spelling variations:
khach thi » khac thi, khach trai, quach thi
vu khach » vu khanh, vu khac, vay khach
thi nang » thi cong, ki nang, thi hanh
van hanh » van thanh, ban hanh, van anh
hanh vu » hanh vi, hanh va, hanh tu
xuc van » duc van, luc van, vuc van
va viet » hoa viet, san viet, mai viet
va cao » va cac, va co, va dao
ve cam » ve cham, ve cac, va cam
nang o » nang co, nang ho, nang ro
o hai » co hai, so hai, o lai
vu va » vu van, tu va, su 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 thi nang o hai. hieu ((ve cam) or (va cao)) xuc van hanh vu va viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu khach thi nang o hai. hieu ((ve cam) OR (va cao)) xuc van hanh vu va viet.
• Adding a wildcard symbol may retrieve word variants: vu khach thi nang o hai. hieu ((ve cam) or (va cao)) xuc van hanh vu va viet*.