Perhaps you should try some spelling variations:
"python using java snippets" » "python using data snippets", "python using java slippers"
"duc van 19 snippets" » "duc va 19 snippets", "duc tan 19 snippets", "duc manh 19 snippets", "duc van 19 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: (((("duc van 19 snippets") or ("python using java snippets"))) or ("locating bug code snippets"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("duc van 19 snippets") OR ("python using java snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( duc van 19 snippets ) or ( python using java snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("duc van 19 snippets") or ("python using java snippets"))) or ("locating bug code snippets"))*.