Perhaps you should try some spelling variations:
khoa thuoc » khong thuoc, khoa hoc, nha thuoc
nhung don » nhung van, nhung bo
khoa toc » khoa hoc, hoa toc, khoa quoc
tieu chi » trien chi, dieu chim, lieu chiu
hieu chi » hieu cac, hieu moi
tu sach » thu sach, su sach, te sach
don oc » dong hoc
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: tu sach ((khoa toc) OR (khoa thuoc)) ((tieu chi) or (hieu chi)) cua ets : nhung don oc vi đai~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ((khoa toc) OR (khoa thuoc)) ((tieu chi) OR (hieu chi)) cua ets : nhung don oc vi đai.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ((khoa toc) OR (khoa thuoc)) ((tieu chi) or (hieu chi)) cua ets : nhung don oc vi đai".
• Adding a wildcard symbol may retrieve word variants: tu sach ((khoa toc) OR (khoa thuoc)) ((tieu chi) or (hieu chi)) cua ets : nhung don oc vi đai*.