Perhaps you should try some spelling variations:
"dan luan cong snippets" » "dan luat cong snippets", "dan luong cong snippets", "dan luan chung snippets", "doanh luan cong snippets", "dung luan cong snippets", "tang luan 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: (((("dan luan 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: (((("dan luan cong snippets") OR ("dung java java snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( dan luan cong snippets ) or ( dung java java snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("dan luan cong snippets") or ("dung java java snippets"))) or ("locating bug code snippets"))*.