Perhaps you should try some spelling variations:
"python using java snippets" » "python using data snippets"
"duy dan toan snippets" » "duy van toan snippets", "duy dan than snippets", "duy manh toan snippets", "duy can toan snippets", "day dan toan 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: (((("duy dan toan snippets") or ("python using java snippets"))) or ("locating bug code snippets"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("duy dan toan snippets") OR ("python using java snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( duy dan toan snippets ) or ( python using java snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("duy dan toan snippets") or ("python using java snippets"))) or ("locating bug code snippets"))*.