Perhaps you should try some spelling variations:
"python using raw snippets" » "python using real snippets", "python using a snippets", "python using low snippets"
"khoa dan code snippets" » "khoa dang code snippets", "hoa dan code snippets", "khoa can code snippets", "khoa dan de snippets"
"locating bug core snippets" » "locating bug code 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: (((("khoa dan code snippets") or ("python using raw snippets"))) or ("locating bug core snippets"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("khoa dan code snippets") OR ("python using raw snippets"))) OR ("locating bug core snippets")).
• Removing quotes may allow a broader search: (((( khoa dan code snippets ) or ( python using raw snippets ))) or ( locating bug core snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("khoa dan code snippets") or ("python using raw snippets"))) or ("locating bug core snippets"))*.