Perhaps you should try some spelling variations:
"luan khoa code slippers" » "khuan khoa code slippers", "toan khoa code slippers", "luan hoan code slippers", "luan khoa cong slippers", "luan khoa co slippers", "luan khoa de slippers"
"dung java java snippets" » "dung va java snippets"
"locating bug code snippets" » "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: (((("luan khoa code slippers") or ("dung java java snippets"))) or ("locating bug code snippets"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("luan khoa code slippers") OR ("dung java java snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( luan khoa code slippers ) or ( dung java java snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("luan khoa code slippers") or ("dung java java snippets"))) or ("locating bug code snippets"))*.