Perhaps you should try some spelling variations:
"cong trong do snippets" » "cong thuong do snippets", "cong trinh do snippets", "dung trong do snippets", "cong trong doi snippets", "cong trong dao snippets", "cong trong 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 java java snippets") or ("cong trong do snippets"))) or ("locating bug code snippets"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("dung java java snippets") OR ("cong trong do snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( dung java java snippets ) or ( cong trong do snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("dung java java snippets") or ("cong trong do snippets"))) or ("locating bug code snippets"))*.