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