Perhaps you should try some spelling variations:
"luan toan de snippets" » "luan hoan de snippets", "xuan toan de snippets", "luan thanh de snippets", "luan toan du snippets", "luan toan ke snippets", "luan toan ve snippets"
"dung java java snippets" » "dung va java 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: (((("luan toan de snippets") or ("dung java java snippets"))) or ("locating bug code snippets"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("luan toan de snippets") OR ("dung java java snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( luan toan de snippets ) or ( dung java java snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("luan toan de snippets") or ("dung java java snippets"))) or ("locating bug code snippets"))*.