Perhaps you should try some spelling variations:
mai viet » thi viet
van hanh » van thanh, ban hanh, van anh
vu khach » vu khanh, vu khac, vay khach
thi hanh » thi thanh
xuc van » duc van, luc van, vuc van
vu sach » vu bach, su sach
ve cam » ve cham, ve cac, ve cai
va cam » va cham, va cac, va cao
hanh o » hanh mo, hanh _, hanh y
vi mai » vi dai, vi tai
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: ((vu sach) or (vu khach)) thi hanh o hoi. hieu ((ve cam) or (va cam)) xuc van hanh vi mai viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((vu sach) OR (vu khach)) thi hanh o hoi. hieu ((ve cam) OR (va cam)) xuc van hanh vi mai viet.
• Adding a wildcard symbol may retrieve word variants: ((vu sach) or (vu khach)) thi hanh o hoi. hieu ((ve cam) or (va cam)) xuc van hanh vi mai viet*.