Perhaps you should try some spelling variations:
"dung java java snippets" » "dung va java snippets"
"dong chi toan snippets" » "dong cho toan snippets", "dong thi toan snippets", "dung chi toan snippets", "dong khi toan snippets", "dong chi thanh snippets", "dong bai toan 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 java java snippets") or ("dong chi toan snippets"))) or ("locating bug code snippets"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("dung java java snippets") OR ("dong chi toan snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( dung java java snippets ) or ( dong chi toan snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("dung java java snippets") or ("dong chi toan snippets"))) or ("locating bug code snippets"))*.