Perhaps you should try some spelling variations:
"quoc khanh java slippers" » "ngoc khanh java slippers", "quoc thinh java slippers", "quoc khanh java slippery", "quoc khanh 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: (((("quoc khanh 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: (((("quoc khanh java slippers") OR ("dung java java snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( quoc khanh java slippers ) or ( dung java java snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("quoc khanh java slippers") or ("dung java java snippets"))) or ("locating bug code snippets"))*.