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