Perhaps you should try some spelling variations:
"dung tran manh slippers" » "dung tren manh slippers", "hung tran manh slippers", "dang tran manh slippers", "dung tran minh slippers", "dung tran thanh slippers", "dung tran van slippers", "dung tran manh slippery", "dung tran manh 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 tran manh 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 tran manh slippers") OR ("dung java java snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( dung tran manh slippers ) or ( dung java java snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("dung tran manh slippers") or ("dung java java snippets"))) or ("locating bug code snippets"))*.