Perhaps you should try some spelling variations:
"so sach nganh ky thuat toan hoc" » "so sach tranh ky thuat toan hoc", "so cac nganh ky thuat toan hoc", "so sach danh ky thuat toan hoc", "so sach ngonh ky thuat toan hoc", "so sach nhah ky thuat toan hoc", "so sach hanh ky thuat toan hoc", "so sach nganh y thuat toan hoc", "so sach nganh xay thuat toan hoc", "so sach nganh ky thuat toan khoa", "so sach nganh ky thuat van hoc", "so sach nganh ky thuat hoa hoc", "so sanh nganh ky thuat toan hoc", "bo sach nganh ky thuat toan hoc", "co sach nganh ky thuat toan hoc"
"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 toan khoa", "so sach ngan ky thuat van hoc", "so sach ngan ky thuat hoa 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 hoc") OR ("so sach ngan ky thuat toan hoc"))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"so sach nganh ky thuat toan hoc\") OR (\"so sach ngan ky thuat toan hoc\"))".
• Removing quotes may allow a broader search: (( so sach nganh ky thuat toan hoc ) OR ( so sach ngan ky thuat toan hoc )).
• Adding a wildcard symbol may retrieve word variants: (("so sach nganh ky thuat toan hoc") OR ("so sach ngan ky thuat toan hoc"))*.