Perhaps you should try some spelling variations:
khoa thuoc » khong thuoc, khoa hoc, nha thuoc
thieu chi » thieu nhi, hieu chi, tieu chi
toc sach » hoc sach, doc sach, thuoc sach
khoa toc » khoa hoc, hoa toc, khoa quoc
nhung bo » nhung bi, nhung bai, nhung don
chi cua » chi cuc, khi cua, cuoi cua
bo oc » bo uoc, bo o
oc vi » hoc vi, doc vi

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