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