Perhaps you should try some spelling variations:
"_ qing zhang snippets" » "_ ming zhang snippets", "_ yang zhang snippets", "_ qing zhang slippers"
"python using java snippets" » "python using data snippets", "python using java slippers"
"locating bug code snippets" » "locating bug code slippers", "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: (((("_ qing zhang snippets") or ("python using java snippets"))) or ("locating bug code snippets"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("_ qing zhang snippets") OR ("python using java snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( _ qing zhang snippets ) or ( python using java snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("_ qing zhang snippets") or ("python using java snippets"))) or ("locating bug code snippets"))*.