Perhaps you should try some spelling variations:
"dung sinh con snippets" » "duong sinh con snippets", "dang sinh con snippets", "dung ninh con snippets", "dung sinh cong snippets", "dung sinh ton snippets", "dung sinh co 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 sinh con 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 sinh con snippets") OR ("dung java java snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( dung sinh con snippets ) or ( dung java java snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("dung sinh con snippets") or ("dung java java snippets"))) or ("locating bug code snippets"))*.