Perhaps you should try some spelling variations:
"python using java snippets" » "python using data snippets", "python using java slippers"
"khoa hat dan snippets" » "hoa hat dan snippets", "khoa ha dan snippets", "khoa kham dan snippets", "khoa hat van snippets", "khoa mat dan snippets", "khoa nhat danh snippets", "khoa hat dan slippers"
"locating bug code snippets" » "locating bug code slippers", "locating bung code snippets", "locating bugs code snippets", "locating bug core snippets"

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: (((("khoa hat dan snippets") or ("python using java snippets"))) or ("locating bug code snippets"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("khoa hat dan snippets") OR ("python using java snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( khoa hat dan snippets ) or ( python using java snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("khoa hat dan snippets") or ("python using java snippets"))) or ("locating bug code snippets"))*.