Perhaps you should try some spelling variations:
khoa thuoc » khong thuoc, khoa hoc, nha thuoc
toc sach » hoc sach, doc sach, thuoc sach
khoa toc » khoa hoc, hoa toc, khoa quoc
hieu khi » hieu chi, thieu nhi, khien khi
nhung bi » nhung gi
khi cua » chi cua, thai cua
ho vi » hoc vi, hoa vi, ho voi

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

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