Perhaps you should try some spelling variations:
"python using java snippets" » "python using data snippets", "python using java slippers"
"van thi khan snippets" » "van thi khanh snippets", "van thi than snippets", "van thi han snippets", "van tai khan snippets", "dan thi khan snippets", "van thu khan snippets", "van thi khan 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: (((("van thi khan snippets") or ("python using java snippets"))) or ("locating bug code snippets"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("van thi khan snippets") OR ("python using java snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( van thi khan snippets ) or ( python using java snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("van thi khan snippets") or ("python using java snippets"))) or ("locating bug code snippets"))*.