Perhaps you should try some spelling variations:
"dung trung he snippets" » "dung trong he snippets", "quang trung he snippets", "truong trung he snippets", "dung trung ha snippets", "dung trung hieu snippets"
"dung using java snippets" » "dung ung java snippets", "dung sinh java snippets", "dung uong java snippets", "dung using data 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 trung he snippets") or ("dung using java snippets"))) or ("locating bug code snippets"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("dung trung he snippets") OR ("dung using java snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( dung trung he snippets ) or ( dung using java snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("dung trung he snippets") or ("dung using java snippets"))) or ("locating bug code snippets"))*.