Perhaps you should try some spelling variations:
"manh dung do snippets" » "manh hung do snippets", "manh tung do snippets", "anh dung do snippets", "manh dung doi snippets", "manh dung co snippets", "manh dung de snippets"
"dung java java snippets" » "dung 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: (((("manh dung do snippets") or ("dung java java snippets"))) or ("locating bug code snippets"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("manh dung do snippets") OR ("dung java java snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( manh dung do snippets ) or ( dung java java snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("manh dung do snippets") or ("dung java java snippets"))) or ("locating bug code snippets"))*.