Perhaps you should try some spelling variations:
thuyet bai » thuyet va
ky thuyet » ly thuyet, li thuyet, ly huyet
sach ngan » sach ngon, sach nha, sach han
thanh ky » hanh ky, than ky, thanh tay
toan hoc » toan khoa, van hoc, hoa hoc
so dinh » do dinh, so sinh, so tinh
co dinh » do dinh
bai hoc » dai hoc
so sach » so sanh, bo sach, co sach
ngan ky » nganh ky, nhan ky, ngan hay

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( ((so dinh) OR (co dinh)) thanh ky thuyet bai hoc ) or ( so sach ngan ky thuat toan hoc ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( ((so dinh) OR (co dinh)) thanh ky thuyet bai hoc ) OR ( so sach ngan ky thuat toan hoc )).
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( ((so dinh) OR (co dinh)) thanh ky thuyet bai hoc ) or ( so sach ngan ky thuat toan hoc ))".
• Adding a wildcard symbol may retrieve word variants: (( ((so dinh) OR (co dinh)) thanh ky thuyet bai hoc ) or ( so sach ngan ky thuat toan hoc ))*.