Perhaps you should try some spelling variations:
"dang tran duc slippers" » "dang thanh duc slippers", "quang tran duc slippers", "hoang tran duc slippers", "dang tran duc slippery", "dang tran duc 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: (((("dang tran duc slippers") or ("dung java java snippets"))) or ("locating bug code snippets"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("dang tran duc slippers") OR ("dung java java snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( dang tran duc slippers ) or ( dung java java snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("dang tran duc slippers") or ("dung java java snippets"))) or ("locating bug code snippets"))*.