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