Perhaps you should try some spelling variations:
"dung minh doan snippets" » "duong minh doan snippets", "dung ninh doan snippets", "dung vinh doan snippets", "dung minh doanh snippets", "dung minh toan snippets", "dung minh don snippets"
"dung java java snippets" » "dung va java snippets"
"locating bug code snippets" » "locating bung code snippets", "locating bugs code snippets", "locating bug core 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: (((("dung minh doan snippets") or ("dung java java snippets"))) or ("locating bug code snippets"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("dung minh doan snippets") OR ("dung java java snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( dung minh doan snippets ) or ( dung java java snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("dung minh doan snippets") or ("dung java java snippets"))) or ("locating bug code snippets"))*.