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