Perhaps you should try some spelling variations:
"duc van code snippets" » "duc van de snippets", "duc van hoe snippets", "duc van cong snippets", "duc va code snippets", "duc tan code snippets", "duc manh code snippets", "duc van 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: (((("duc van 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: (((("duc van code snippets") OR ("python using a snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( duc van code snippets ) or ( python using a snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("duc van code snippets") or ("python using a snippets"))) or ("locating bug code snippets"))*.