Perhaps you should try some spelling variations:
"dung danh du snippets" » "dung doanh du snippets", "dung dan du snippets", "dung dang du snippets", "dung danh dau snippets", "dung danh tu snippets", "dung dinh du 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 danh du 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 danh du snippets") OR ("hang java java snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( dung danh du snippets ) or ( hang java java snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("dung danh du snippets") or ("hang java java snippets"))) or ("locating bug code snippets"))*.