Perhaps you should try some spelling variations:
"dung tra trinh slippers" » "dung qua trinh slippers", "dung tri trinh slippers", "dung tru trinh slippers", "dung tren trinh slippers", "dung tra trinh slippery", "dung tra trinh grippers"
"dung luan code snippets" » "dung luan cong snippets", "dung luan che snippets", "dung luan de snippets"
"locating bug code snippets" » "locating bung code snippets", "locating bugs code snippets"

You may be able to get more results by adjusting your search query.

• If you are trying to use Boolean operators, they must be ALL CAPS: (((("dung tra trinh slippers") OR ("dung luan code snippets"))) OR ("locating bug code snippets"))~.
• Removing quotes may allow a broader search: (((( dung tra trinh slippers ) or ( dung luan code snippets ))) or ( locating bug code snippets ))~.
• Adding a wildcard symbol may retrieve word variants: (((("dung tra trinh slippers") or ("dung luan code snippets"))) or ("locating bug code snippets"))*.