Perhaps you should try some spelling variations:
"doi ngan java slippers" » "doi ngu java slippers", "doi nganh java slippers", "doi nhan java slippers", "dai ngan java slippers", "doi ngan java slippery", "doi ngan 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: (((("doi ngan 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: (((("doi ngan java slippers") OR ("dung java java snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( doi ngan java slippers ) or ( dung java java snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("doi ngan java slippers") or ("dung java java snippets"))) or ("locating bug code snippets"))*.