Perhaps you should try some spelling variations:
"so sach nganh ky thuat van hoc" » "so sach ngan ky thuat van hoc", "so sach tranh ky thuat van hoc", "so cac nganh ky thuat van hoc", "so sach nganh ky thuat san hoc", "so sach nganh ky thuat va hoc", "so sach nganh ky thuat ban hoc", "so sach nganh y thuat van hoc", "so sach nganh xay thuat van hoc", "so sach hanh ky thuat van hoc", "so sanh nganh ky thuat van hoc", "bo sach nganh ky thuat van hoc", "co sach nganh ky thuat van hoc", "so sach nganh ky thuat van hoa"
"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 toan khoa", "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"

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