Perhaps you should try some spelling variations:
"dun nang cong snippets" » "dun nang song snippets", "dun dang cong snippets", "dun hang cong snippets", "dung nang cong snippets", "den nang cong snippets", "luan nang cong 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: (((("dun nang cong snippets") or ("dung java java snippets"))) or ("locating bug code snippets"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("dun nang cong snippets") OR ("dung java java snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( dun nang cong snippets ) or ( dung java java snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("dun nang cong snippets") or ("dung java java snippets"))) or ("locating bug code snippets"))*.