Perhaps you should try some spelling variations:
"phap luan code snippets" » "phap luat code snippets", "phap hoan code snippets", "phap luan cong snippets", "phap luan che snippets", "phap luan de snippets", "phap luan code slippers"
"dung cfd code snippets" » "dung cho code snippets", "dung cua code snippets", "dung co code snippets", "dung cfd code slippers"
"locating bug code snippets" » "locating bug code slippers", "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: (((("phap luan code snippets") or ("dung cfd code snippets"))) or ("locating bug code snippets"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("phap luan code snippets") OR ("dung cfd code snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( phap luan code snippets ) or ( dung cfd code snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("phap luan code snippets") or ("dung cfd code snippets"))) or ("locating bug code snippets"))*.