Perhaps you should try some spelling variations:
"so sach nganh ky thuat toan khoa" » "so sach tranh ky thuat toan khoa", "so cac nganh ky thuat toan khoa", "so sach danh ky thuat toan khoa", "so sach ngonh ky thuat toan khoa", "so sach nhah ky thuat toan khoa", "so sach hanh ky thuat toan khoa", "so sach nganh y thuat toan khoa", "so sach nganh xay thuat toan khoa", "so sanh nganh ky thuat toan khoa", "bo sach nganh ky thuat toan khoa", "co sach nganh ky thuat toan khoa"
"so sach ngan ky thuat toan hoc" » "so sach ngon ky thuat toan hoc", "so sach nha ky thuat toan hoc", "so sach han ky thuat toan hoc", "so sach ngan ky thuat van hoc", "so sach ngan ky thuat hoa hoc", "so sach ngan ky thuat tin hoc", "so sanh ngan ky thuat toan hoc", "bo sach ngan ky thuat toan hoc", "co sach ngan ky thuat toan hoc", "so sach nhan ky thuat toan hoc", "so sach ngan hay thuat toan hoc", "so sach nganh ke thuat toan hoc"

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

• Performing a fuzzy search may retrieve terms with similar spellings: (("so sach nganh ky thuat toan khoa") or ("so sach ngan ky thuat toan hoc"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("so sach nganh ky thuat toan khoa") OR ("so sach ngan ky thuat toan hoc")).
• Removing quotes may allow a broader search: (( so sach nganh ky thuat toan khoa ) or ( so sach ngan ky thuat toan hoc )).
• Adding a wildcard symbol may retrieve word variants: (("so sach nganh ky thuat toan khoa") or ("so sach ngan ky thuat toan hoc"))*.