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