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