Perhaps you should try some spelling variations:
"khoa doc trinh slippers" » "khoa doc tinh slippers", "khoa doi trinh slippers", "khoa hoc trinh slippers", "khoa duoc trinh slippers", "khoa doc trinh slippery", "khoa doc trinh 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: (((("khoa doc trinh slippers") or ("dung java java snippets"))) or ("locating bug code snippets"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("khoa doc trinh slippers") OR ("dung java java snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( khoa doc trinh slippers ) or ( dung java java snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("khoa doc trinh slippers") or ("dung java java snippets"))) or ("locating bug code snippets"))*.