Perhaps you should try some spelling variations:
"cong nhan co snippets" » "cong nhat co snippets", "cong thanh co snippets", "cong san co snippets", "cong nhan con snippets", "cong phan co snippets", "cong nhan mo 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: (((("cong nhan co snippets") or ("dung java java snippets"))) or ("locating bug code snippets"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("cong nhan co snippets") OR ("dung java java snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( cong nhan co snippets ) or ( dung java java snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("cong nhan co snippets") or ("dung java java snippets"))) or ("locating bug code snippets"))*.