Perhaps you should try some spelling variations:
nhung dong » nhung don, nhung cong, nhung dung
kieu cuoi » dieu tuoi, viec cuoi, kieu cao
toc sach » hoc sach, doc sach, thuoc sach
khoa hoc » hoa hoc
cuoi cua » hoi cua, doi cua, co cua
dong so » dong son, dong co, cong so
so vi » so voi, so va, so di

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((te sach) OR (toc sach)) ((khoa hoc) or (nha nuoc)) kieu cuoi cua ets : nhung dong so vi đai~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((te sach) OR (toc sach)) ((khoa hoc) OR (nha nuoc)) kieu cuoi cua ets : nhung dong so vi đai.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((te sach) OR (toc sach)) ((khoa hoc) or (nha nuoc)) kieu cuoi cua ets : nhung dong so vi đai".
• Adding a wildcard symbol may retrieve word variants: ((te sach) OR (toc sach)) ((khoa hoc) or (nha nuoc)) kieu cuoi cua ets : nhung dong so vi đai*.