Perhaps you should try some spelling variations:
"trac cong thanh snippets" » "trac dong thanh snippets", "trac cong trinh snippets", "trac cong tan snippets", "tran cong thanh snippets", "tra cong thanh snippets", "trao cong thanh snippets", "trac cong thanh slippers"
"dung java java snippets" » "dung va java snippets", "dung java java slippers"
"locating bug code snippets" » "locating bug code slippers", "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: (((("trac cong thanh snippets") or ("dung java java snippets"))) or ("locating bug code snippets"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("trac cong thanh snippets") OR ("dung java java snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( trac cong thanh snippets ) or ( dung java java snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("trac cong thanh snippets") or ("dung java java snippets"))) or ("locating bug code snippets"))*.