Perhaps you should try some spelling variations:
"python using java snippets" » "python using data snippets"
"ngu hoi den snippets" » "ngu thoi den snippets", "ngu hoc den snippets", "ngu noi den snippets", "ngu hoi dien snippets", "ngu hoi dan snippets", "ngu moi 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: (((("ngu hoi 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: (((("ngu hoi den snippets") OR ("python using java snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( ngu hoi den snippets ) or ( python using java snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("ngu hoi den snippets") or ("python using java snippets"))) or ("locating bug code snippets"))*.