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