Perhaps you should try some spelling variations:
sach khoa » bach khoa, sach nha, sinh khoa
hoc thieu » toc thieu, hoc hien
thieu chi » thieu nhi, hieu chi, tieu chi
anh khoa » doanh khoa, hang khoa
nhung bi » nhung bai, nhung gi
chi cua » chi cuc, khi cua, cuoi cua
duoc va » nuoc va, duc va, duoc ma
doc vi » hoc vi, don vi, doc va

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

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