Perhaps you should try some spelling variations:
"python using java snippets" » "python using data snippets"
"van luc hoan snippets" » "van duc hoan snippets", "van luan hoan snippets", "van duc hoang snippets", "van loc hoan snippets", "van lu hoan 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: (((("van luc hoan 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 luc hoan snippets") OR ("python using java snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( van luc hoan snippets ) or ( python using java snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("van luc hoan snippets") or ("python using java snippets"))) or ("locating bug code snippets"))*.