Perhaps you should try some spelling variations:
"dung muon hoc snippets" » "cung muon hoc snippets", "dung nguon hoc snippets", "dung huong hoc snippets", "dung mon hoc snippets", "dung duong hoc snippets", "dung tuong hoc 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: (((("dung muon hoc snippets") or ("dung java java snippets"))) or ("locating bug code snippets"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("dung muon hoc snippets") OR ("dung java java snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( dung muon hoc snippets ) or ( dung java java snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("dung muon hoc snippets") or ("dung java java snippets"))) or ("locating bug code snippets"))*.