Perhaps you should try some spelling variations:
"python using java snippets" » "python using data snippets"
"doan van son snippets" » "doan va son snippets", "hoang van son snippets", "luan van son snippets", "doan van dong snippets", "doan van cong snippets", "doan van sung snippets"
"locating bug code snippets" » "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: (((("doan van son snippets") or ("python using java snippets"))) or ("locating bug code snippets"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("doan van son snippets") OR ("python using java snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( doan van son snippets ) or ( python using java snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("doan van son snippets") or ("python using java snippets"))) or ("locating bug code snippets"))*.