Perhaps you should try some spelling variations:
nhung dong » nhung cong, nhung dung, nhung bong
nhung don » nhung van, nhung bo
sach khoa » bach khoa, sach nha, anh khoa
thu sach » tu sach, thuat sach, thuoc sach
khoa hoc » hoa hoc
dieu cao » dieu can, dieu cac, dieu co
dieu cam » dieu can, dieu cua, diem cau
so vat » so van

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

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