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