Perhaps you should try some spelling variations:
"dung ninh toan snippets" » "dung vinh toan snippets", "quang ninh toan snippets", "dung dich toan snippets", "dung tinh toan snippets", "dung nin toan snippets", "dung hinh toan 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: (((("dung ninh toan snippets") or ("dung java java snippets"))) or ("locating bug code snippets"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("dung ninh toan snippets") OR ("dung java java snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( dung ninh toan snippets ) or ( dung java java snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("dung ninh toan snippets") or ("dung java java snippets"))) or ("locating bug code snippets"))*.