Perhaps you should try some spelling variations:
"python using java snippets" » "python using data snippets"
"van cong voi snippets" » "van dong voi snippets", "van phong voi snippets", "phan cong voi snippets", "van cong goi snippets", "van cong noi snippets", "van cong soi 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: (((("van cong voi 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 cong voi snippets") OR ("python using java snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( van cong voi snippets ) or ( python using java snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("van cong voi snippets") or ("python using java snippets"))) or ("locating bug code snippets"))*.