Perhaps you should try some spelling variations:
"mat cao code snippets" » "mat cao cong snippets", "mat cao de snippets", "mat cfd code snippets", "mat can code snippets", "mat co code snippets", "chat cao code snippets", "mat cao code 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"

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: (((("mat cao code snippets") or ("python using a snippets"))) or ("locating bug code snippets"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("mat cao code snippets") OR ("python using a snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( mat cao code snippets ) or ( python using a snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("mat cao code snippets") or ("python using a snippets"))) or ("locating bug code snippets"))*.