Perhaps you should try some spelling variations:
"dung cong luc slippers" » "dung trong luc slippers", "dung dong luc slippers", "dung cong suc slippers", "dung cong duc slippers", "dung cong luc slippery", "dung cong luc grippers"
"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: (((("dung cong luc slippers") or ("dung java java snippets"))) or ("locating bug code snippets"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("dung cong luc slippers") OR ("dung java java snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( dung cong luc slippers ) or ( dung java java snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("dung cong luc slippers") or ("dung java java snippets"))) or ("locating bug code snippets"))*.