Perhaps you should try some spelling variations:
hoach hoi » hoc hoi, hoach ha
sach moi » bach mai, sach bai, cac moi
sach hoi » cach thoi, sach bai, sach han
hoc sach » hoc sinh, hoc cac, hoc anh
sach doi » sach dao, sach bai, sach dat
doi hoat » toi hoat, doi hoa, doi hoac
chuc » thuc, chu, chua

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

• If you are trying to use Boolean operators, they must be ALL CAPS: (( co ((sach moi) OR (sach hoi)) hoa ) OR ((( hoc sach doi hoat ) OR ( ke hoach hoi chuc ))))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( co ((sach moi) OR (sach hoi)) hoa ) or ((( hoc sach doi hoat ) or ( ke hoach hoi chuc ))))~".
• Adding a wildcard symbol may retrieve word variants: (( co ((sach moi) OR (sach hoi)) hoa ) or ((( hoc sach doi hoat ) or ( ke hoach hoi chuc ))))*.