Perhaps you should try some spelling variations:
"dung vien chi snippets" » "duong vien chi snippets", "dung viet chi snippets", "dung tien chi snippets", "dung vien nhi snippets", "dung kien chi snippets", "dung viec chi 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 vien chi 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 vien chi snippets") OR ("dung java java snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( dung vien chi snippets ) or ( dung java java snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("dung vien chi snippets") or ("dung java java snippets"))) or ("locating bug code snippets"))*.