Perhaps you should try some spelling variations:
"tran khoa code snippets" » "toan khoa code snippets", "san khoa code snippets", "nhan khoa code snippets", "tran khoa cong snippets", "tran khoa co snippets", "tran khoa de snippets", "tran khoa code 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"

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: (((("tran khoa code snippets") or ("dung java java snippets"))) or ("locating bug code snippets"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("tran khoa code snippets") OR ("dung java java snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( tran khoa code snippets ) or ( dung java java snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("tran khoa code snippets") or ("dung java java snippets"))) or ("locating bug code snippets"))*.