Perhaps you should try some spelling variations:
"trinh van con snippets" » "trinh han con snippets", "trinh quan con snippets", "trinh toan con snippets", "trinh van cong snippets", "trinh van bon snippets", "trinh van co snippets"
"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 van con snippets") or ("dung cfd code snippets"))) or ("locating bug code snippets"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("trinh van con snippets") OR ("dung cfd code snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( trinh van con snippets ) or ( dung cfd code snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("trinh van con snippets") or ("dung cfd code snippets"))) or ("locating bug code snippets"))*.