Perhaps you should try some spelling variations:
doanh day » doanh dao, doanh tai, doanh va
cap nuoc » dat nuoc
hieu van » hieu va, thien van, lieu va
cac nuoc » hoc nuoc, dat nuoc, cua nuoc
ta doanh » va doanh, te doanh, ty doanh
te sach » toc sach
ky lang » ky nang, ky dang, ky tang
lang ha » long ha
day cua » dai cua
cac toc » cac toi, cac thoi
sach ky » sac ky, sach y, sach ty
cua te » cua tu
ha hoi » hoa hoi, ha noi, xa hoi

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 ky lang ha hoi. hieu van ((cac toc) OR (((cac nuoc) OR (cap nuoc)))) ta doanh day cua te~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ky lang ha hoi. hieu van ((cac toc) or (((cac nuoc) OR (cap nuoc)))) ta doanh day cua te~".
• Adding a wildcard symbol may retrieve word variants: te sach ky lang ha hoi. hieu van ((cac toc) or (((cac nuoc) OR (cap nuoc)))) ta doanh day cua te*.