Perhaps you should try some spelling variations:
"python using java snippets" » "python using data snippets"
"khach van do snippets" » "khach san do snippets", "khanh van do snippets", "khach hang do snippets", "khach van dao snippets", "khach van de snippets", "khach van du 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: (((("khach van do snippets") or ("python using java snippets"))) or ("locating bug code snippets"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("khach van do snippets") OR ("python using java snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( khach van do snippets ) or ( python using java snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("khach van do snippets") or ("python using java snippets"))) or ("locating bug code snippets"))*.