Perhaps you should try some spelling variations:
"so danh tranh ky thuat toan khoa" » "so canh tranh ky thuat toan khoa", "so danh thanh ky thuat toan khoa", "so lanh tranh ky thuat toan khoa", "so danh trinh ky thuat toan khoa", "so danh nganh ky thuat toan khoa", "do danh tranh ky thuat toan khoa", "so sanh tranh ky thuat toan khoa", "so dan tranh ky thuat toan khoa", "so danh tranh ky thuat tran khoa"
"do xanh hanh ky thuat toan khoa" » "do danh thanh ky thuat toan khoa", "do ban hanh ky thuat toan khoa", "do van hanh ky thuat toan khoa", "do sanh hanh ky thuat toan khoa", "do danh hanh ky thuat toan khoa", "do anh hanh ky thuat toan khoa", "do xanh hanh kem thuat toan khoa", "do xanh hanh ky thuat tran khoa"

Try widening your search to All Fields.

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

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