Perhaps you should try some spelling variations:
"dan viet code snippets" » "dan viet co snippets", "dan viet some snippets", "danh viet code snippets", "san viet code snippets", "dao viet code snippets", "dan viet code slippers"
"dung luan code snippets" » "dung luan cong snippets", "dung luan che snippets", "dung luan de snippets", "dung luan code 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: (((("dan viet code snippets") or ("dung luan code snippets"))) or ("locating bug code snippets"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("dan viet code snippets") OR ("dung luan code snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( dan viet code snippets ) or ( dung luan code snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("dan viet code snippets") or ("dung luan code snippets"))) or ("locating bug code snippets"))*.