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