Perhaps you should try some spelling variations:
"dung ngan zheng slippers" » "dung ngan hang slippers", "dung xuan zheng slippers", "dung nhan zheng slippers", "dung luan zheng slippers", "dung ngan zheng slippery", "dung ngan zheng 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 ngan zheng 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 ngan zheng slippers") OR ("dung java java snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( dung ngan zheng slippers ) or ( dung java java snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("dung ngan zheng slippers") or ("dung java java snippets"))) or ("locating bug code snippets"))*.