Perhaps you should try some spelling variations:
"dung tren duc slippers" » "dung trong duc slippers", "dung trung duc slippers", "dung tran duc slippers", "dung ren duc slippers", "dung tien duc slippers", "dung tren duc slippery", "dung tren duc 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 tren duc 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 tren duc slippers") OR ("dung java java snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( dung tren duc slippers ) or ( dung java java snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("dung tren duc slippers") or ("dung java java snippets"))) or ("locating bug code snippets"))*.