Perhaps you should try some spelling variations:
"dung tri doan snippets" » "dung tri code snippets", "dung tai doan snippets", "dung tren doan snippets", "nhung tri doan snippets", "dung tri doanh snippets", "dung thi doan snippets", "dung tri hoan 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 tri 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 tri doan snippets") OR ("dung java java snippets"))) OR ("locating bug core snippets")).
• Removing quotes may allow a broader search: (((( dung tri doan snippets ) or ( dung java java snippets ))) or ( locating bug core snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("dung tri doan snippets") or ("dung java java snippets"))) or ("locating bug core snippets"))*.