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