Perhaps you should try some spelling variations:
"so sach nganh ma thuat toan hoc" » "so sach ngan ma thuat toan hoc", "so sach tranh ma thuat toan hoc", "so cac nganh ma thuat toan hoc", "so sach nganh mac thuat toan hoc", "so sach nganh hoa thuat toan hoc", "so sach nganh y thuat toan hoc", "so sach nganh my thuat toan hoc", "so sach nganh va thuat toan hoc", "so sach nganh mi thuat toan hoc", "so sach nganh ma thuat van hoc", "so sach nganh ma thuat hoa hoc", "so sach nganh ma thuat tin hoc", "so sanh nganh ma thuat toan hoc", "bo sach nganh ma thuat toan hoc", "co sach nganh ma thuat toan hoc"
"so sach ngon ky thuat toan khoa" » "so sach ngan ky thuat toan khoa", "so danh ngon ky thuat toan khoa", "so canh ngon ky thuat toan khoa", "so sanh ngon ky thuat toan khoa", "bo sach ngon ky thuat toan khoa", "co sach ngon ky thuat toan khoa", "so sach ngon keo thuat toan khoa"

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