Perhaps you should try some spelling variations:
"dung hieu da snippets" » "dong hieu da snippets", "dung tieu da snippets", "trung hieu da snippets", "dung hieu dac snippets", "dung hieu dia snippets", "dung hieu va snippets"
"hang java java snippets" » "hang 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 hieu da snippets") or ("hang java java snippets"))) or ("locating bug code snippets"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("dung hieu da snippets") OR ("hang java java snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( dung hieu da snippets ) or ( hang java java snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("dung hieu da snippets") or ("hang java java snippets"))) or ("locating bug code snippets"))*.