Perhaps you should try some spelling variations:
khoa thuoc » khong thuoc, khoa hoc, nha thuoc
thuoc sach » hoc sach, nuoc sach, thuat sach
khoa quoc » khoa hoc, hoa duoc, hoc quoc
thieu chi » thieu nhi, hieu chi, tieu chi
khoa toc » khoa hoc, hoa toc, khoa duoc
nhung bo » nhung bi, nhung bai, nhung don
chi cua » chi cuc, khi cua, cuoi cua
bo duoc » co duoc, bo quoc, bo uoc
duoc li » duoc si, duoc ly, duoc lieu

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