Perhaps you should try some spelling variations:
"trinh toan co snippets" » "tinh toan co snippets", "thanh toan co snippets", "trinh han co snippets", "trinh toan cao snippets", "trinh toan ho snippets", "trinh 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: (((("trinh 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: (((("trinh toan co snippets") OR ("dung java java snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( trinh toan co snippets ) or ( dung java java snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("trinh toan co snippets") or ("dung java java snippets"))) or ("locating bug code snippets"))*.