Perhaps you should try some spelling variations:
"dung luan code snippets" » "dung luan cong snippets", "dung luan che snippets", "dung luan de snippets", "dung luan code slippers"
"sach xa code snippets" » "sach dao code snippets", "sach nha code snippets", "sach bai code snippets", "sach xa 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: (((("sach xa 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: (((("sach xa code snippets") OR ("dung luan code snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( sach xa code snippets ) or ( dung luan code snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("sach xa code snippets") or ("dung luan code snippets"))) or ("locating bug code snippets"))*.