Perhaps you should try some spelling variations:
thieu chi » thieu nhi, tieu chi, thu chi
khoa hoc » hoa hoc
nhung bi » nhung bai, nhung gi
hieu chi » hieu cac, hieu moi
anh khoa » doanh khoa, hang khoa
thu anh » thuy anh, thu canh, thu oanh
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 anh khoa hoc ((thieu chi) OR (hieu 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 anh khoa hoc ((thieu chi) OR (hieu 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 anh khoa hoc ((thieu chi) OR (hieu chi)) cua ets : nhung bi ((doc vi) or (duoc va)) đai".
• Adding a wildcard symbol may retrieve word variants: thu anh khoa hoc ((thieu chi) OR (hieu chi)) cua ets : nhung bi ((doc vi) or (duoc va)) đai*.