Perhaps you should try some spelling variations:
"dung viet dat slippers" » "nang viet dat slippers", "cong viet dat slippers", "mang viet dat slippers", "dung viec dat slippers", "dung viet da slippers", "dung viet dao slippers", "dung viet dat slippery", "dung viet dat 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 viet dat 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 viet dat slippers") OR ("dung java java snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( dung viet dat slippers ) or ( dung java java snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("dung viet dat slippers") or ("dung java java snippets"))) or ("locating bug code snippets"))*.