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