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