Perhaps you should try some spelling variations:
"luan viet java slippers" » "luat viet java slippers", "xuan viet java slippers", "quan viet java slippers", "luan viet va slippers", "luan viet java slippery", "luan viet 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: (((("luan viet 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: (((("luan viet java slippers") OR ("dung java java snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( luan viet java slippers ) or ( dung java java snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("luan viet java slippers") or ("dung java java snippets"))) or ("locating bug code snippets"))*.