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