Perhaps you should try some spelling variations:
"phap toan co snippets" » "phap hoan co snippets", "phap luan co snippets", "tap toan co snippets", "phap toan cao snippets", "phap toan ho snippets", "phap toan 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: (((("phap toan co snippets") or ("dung java java snippets"))) or ("locating bug code snippets"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("phap toan co snippets") OR ("dung java java snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( phap toan co snippets ) or ( dung java java snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("phap toan co snippets") or ("dung java java snippets"))) or ("locating bug code snippets"))*.