Perhaps you should try some spelling variations:
sach khoa » bach khoa, sach nha, sinh khoa
hoc thieu » toc thieu
anh khoa » doanh khoa, hang khoa
nghi cua » nghia cua, nghe cua, ngai cua
nhung bo » nhung bi, nhung bai, nhung don
bo doi » bo di, bo noi, co doi
doi vi » doi voi, doi vai, doi va

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

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