Perhaps you should try some spelling variations:
thuoc sach » hoc sach, nuoc sach, thuat sach
thieu chi » thieu nhi, hieu chi, tieu chi
khoa toc » hoa toc, khoa thuoc, khoa quoc
khoa hoc » hoa hoc
chi cua » chi cuc, khi cua, cuoi cua
bo duoc » co duoc, bo uoc, do duoc
bo quoc » bo uoc, ho quoc, hoc quoc

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

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