Perhaps you should try some spelling variations:
"python using java snippets" » "python using data snippets"
"van toi hoi snippets" » "van tai hoi snippets", "van thi hoi snippets", "van toan hoi snippets", "van doi hoi snippets", "van hoi hoi 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 toi hoi 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 toi hoi snippets") OR ("python using java snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( van toi hoi snippets ) or ( python using java snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("van toi hoi snippets") or ("python using java snippets"))) or ("locating bug code snippets"))*.