Perhaps you should try some spelling variations:
hieu khi » hieu chi, thieu nhi, khien khi
khoa toc » khoa hoc, khoa thuoc, khoa quoc
nhung bo » nhung bi, nhung bai, nhung don
hoc cac » hoc cao
khi cua » chi cua, thai cua
hoa toc » hoa hoc, ho toc, hoa doc
hon vi » chon vi, don vi, hon va
hon ai » hon gai, hong hai, khong ai

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc cac ((khoa toc) or (hoa toc)) hieu khi cua ets : nhung bo ((hon vi) OR (hon ai)) đai~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc cac ((khoa toc) OR (hoa toc)) hieu khi cua ets : nhung bo ((hon vi) OR (hon ai)) đai.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc cac ((khoa toc) or (hoa toc)) hieu khi cua ets : nhung bo ((hon vi) OR (hon ai)) đai".
• Adding a wildcard symbol may retrieve word variants: hoc cac ((khoa toc) or (hoa toc)) hieu khi cua ets : nhung bo ((hon vi) OR (hon ai)) đai*.