Perhaps you should try some spelling variations:
thieu chi » thieu nhi, hieu chi, tieu chi
khoa toc » hoa toc, khoa thuoc, khoa quoc
khoa hoc » hoa hoc
nhung bo » nhung bi, nhung bai, nhung don
tu sach » thu sach, te sach, tu cach
su sach » so sach, vu sach
chi cua » chi cuc, khi cua, cuoi cua
bo doc » bo duoc, bo doi, bo oc
doc va » duoc va, hoc va, duc va

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