Perhaps you should try some spelling variations:
"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 nganh ky thuat toan hoc", "so sach nhan ky thuat toan hoc", "so sach ngan hay thuat toan hoc"
"so sach hanh ky thuat toan hoc" » "so sach danh ky thuat toan hoc", "so sach han ky thuat toan hoc", "so sac hanh ky thuat toan hoc", "so sach hanh ky thuat toan khoa", "so sach hanh ky thuat van hoc", "so sach hanh ky thuat hoa hoc", "so sanh hanh ky thuat toan hoc", "bo sach hanh ky thuat toan hoc", "co sach hanh ky thuat toan hoc", "so sach hanh kem 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 hanh ky thuat toan hoc") or ("so sach ngan ky thuat toan hoc"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("so sach hanh ky thuat toan hoc") OR ("so sach ngan ky thuat toan hoc")).
• Removing quotes may allow a broader search: (( so sach hanh ky thuat toan hoc ) or ( so sach ngan ky thuat toan hoc )).
• Adding a wildcard symbol may retrieve word variants: (("so sach hanh ky thuat toan hoc") or ("so sach ngan ky thuat toan hoc"))*.