Perhaps you should try some spelling variations:
"dung kieu doan snippets" » "duong kieu doan snippets", "dung hieu doan snippets", "dung tieu doan snippets", "dung kiem toan snippets", "dung ket doan snippets", "dung kieu van 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 kieu 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 kieu doan snippets") OR ("dung java java snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( dung kieu doan snippets ) or ( dung java java snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("dung kieu doan snippets") or ("dung java java snippets"))) or ("locating bug code snippets"))*.