Perhaps you should try some spelling variations:
"trinh toan trac slippers" » "tinh toan trac slippers", "thanh toan trac slippers", "trinh han trac slippers", "trinh toan tran slippers", "trinh thoan tran slippers", "trinh toan tap slippers", "trinh toan trac slippery", "trinh toan trac grippers"
"dung cfd code snippets" » "dung cho code snippets", "dung cua code snippets", "dung co code snippets", "dung cfd core snippets"
"locating bug code snippets" » "locating bug core snippets", "locating bung code snippets", "locating bugs code 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 trac slippers") or ("dung cfd code snippets"))) or ("locating bug code snippets"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("trinh toan trac slippers") OR ("dung cfd code snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( trinh toan trac slippers ) or ( dung cfd code snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("trinh toan trac slippers") or ("dung cfd code snippets"))) or ("locating bug code snippets"))*.