Perhaps you should try some spelling variations:
"trinh toan hoc snippets" » "tinh toan hoc snippets", "thanh toan hoc snippets", "trinh han hoc snippets", "trinh toan khoa snippets", "trinh van hoc snippets", "trinh hoa 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"

You may be able to get more results by adjusting your search query.

• The words AND, OR and NOT may confuse the search; try adding quotes: "((((\"trinh toan hoc snippets\") OR (\"dung java java snippets\"))) OR (\"locating bug code snippets\"))~".
• Removing quotes may allow a broader search: (((( trinh toan hoc snippets ) OR ( dung java java snippets ))) OR ( locating bug code snippets ))~.
• Adding a wildcard symbol may retrieve word variants: (((("trinh toan hoc snippets") OR ("dung java java snippets"))) OR ("locating bug code snippets"))*.