Perhaps you should try some spelling variations:
khoa sinh » hoa sinh, khoe sinh, khoa hinh
sach bao » sach dao, sach bai, sach bac
cau khoa » cuu khoa, cu khoa, cau hoa
gioi cau » gioi chau, gioi cam, gioi can
hoach ha » hoach va, hoach xay, hoach hoi
dan dung » van dung, tin dung, ap dung
dan dong » van dong, dao dong, hanh dong
me gioi » me giai, ve gioi, me nguoi
tu sach » thu sach, su sach, te sach
bao me » bao ve, ba me, bo me
ha me » cha me, ba me, ha le

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( tu sach bao me gioi ((dan dong) OR (dan dung)) minh ) or ( thu hoach ha me gioi cau khoa sinh ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( tu sach bao me gioi ((dan dong) OR (dan dung)) minh ) OR ( thu hoach ha me gioi cau khoa sinh )).
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( tu sach bao me gioi ((dan dong) OR (dan dung)) minh ) or ( thu hoach ha me gioi cau khoa sinh ))".
• Adding a wildcard symbol may retrieve word variants: (( tu sach bao me gioi ((dan dong) OR (dan dung)) minh ) or ( thu hoach ha me gioi cau khoa sinh ))*.