Perhaps you should try some spelling variations:
"trinh van code snippets" » "trinh han code snippets", "trinh quan code snippets", "trinh toan code snippets", "trinh van de snippets", "trinh van hoe snippets", "trinh van cong snippets", "trinh van code slippers"
"dung luat data snippets" » "dung luan data snippets", "dung quat data snippets", "dung cua data snippets", "dung luat dat snippets", "dung luat dan snippets", "dung luat dau snippets", "dung luat data 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: (((("trinh van code snippets") or ("dung luat data snippets"))) or ("locating bug code snippets"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("trinh van code snippets") OR ("dung luat data snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( trinh van code snippets ) or ( dung luat data snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("trinh van code snippets") or ("dung luat data snippets"))) or ("locating bug code snippets"))*.