Perhaps you should try some spelling variations:
vu khach » vu khanh, vu khac, vay khach
thuc day » thuc dan, thuc vat
day hanh » day nhanh, day thanh, dao hanh
vu sach » vu bach, su sach
hieu ve » hieu va, hieu van
su tien » su kien, su hien, tu tieng
v nang » va nang, vu nang, van nang
x hoi » xa hoi, o hoi, x ho
vi su » va su, ve su, ki su

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

• If you are trying to use Boolean operators, they must be ALL CAPS: ((vu sach) OR (vu khach)) v nang x hoi. ((hieu ve) OR (hieu qua)) am thuc day hanh vi su tien~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((vu sach) OR (vu khach)) v nang x hoi. ((hieu ve) or (hieu qua)) am thuc day hanh vi su tien~".
• Adding a wildcard symbol may retrieve word variants: ((vu sach) OR (vu khach)) v nang x hoi. ((hieu ve) or (hieu qua)) am thuc day hanh vi su tien*.