Perhaps you should try some spelling variations:
doanh vi » doanh va, doanh vien, doanh tai
nuoc van » nuoc va, nuoc san, luoc van
cac nuoc » cap nuoc, hoc nuoc, dat nuoc
hieu van » hieu va, thien van, lieu va
te sach » toc sach
doan vi » doan va, don vi, doan thi
van cac » van hac, van cau, van bac
luy tre » luyen tre
sach v » sach va, sach y, sach 2
v nang » va nang, vu nang, van nang
o hoi » co hoi, o hoc, o hai

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: te sach v nang ((5 hoi) OR (o hoi)). hieu van cac nuoc van ((doanh vi) OR (doan vi)) luy tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach v nang ((5 hoi) or (o hoi)). hieu van cac nuoc van ((doanh vi) OR (doan vi)) luy tre~".
• Adding a wildcard symbol may retrieve word variants: te sach v nang ((5 hoi) or (o hoi)). hieu van cac nuoc van ((doanh vi) OR (doan vi)) luy tre*.