Perhaps you should try some spelling variations:
"doan va toan snippets" » "doan va code snippets", "doan van toan snippets", "doan bai toan snippets", "doan tap toan snippets", "doanh va toan snippets", "dan va toan snippets", "soan va toan snippets"
"locating bug core snippets" » "locating bug code snippets"
"python using java snippets" » "python using data 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: (((("doan va toan snippets") or ("python using java snippets"))) or ("locating bug core snippets"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("doan va toan snippets") OR ("python using java snippets"))) OR ("locating bug core snippets")).
• Removing quotes may allow a broader search: (((( doan va toan snippets ) or ( python using java snippets ))) or ( locating bug core snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("doan va toan snippets") or ("python using java snippets"))) or ("locating bug core snippets"))*.