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