Perhaps you should try some spelling variations:
"phan viet code snippets" » "phap viet code snippets", "han viet code snippets", "pham viet code snippets", "phan viet co snippets", "phan viet some snippets", "phan viet 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: (((("phan viet 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: (((("phan viet code snippets") OR ("python using a snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( phan viet code snippets ) or ( python using a snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("phan viet code snippets") or ("python using a snippets"))) or ("locating bug code snippets"))*.