Perhaps you should try some spelling variations:
"ninh viet code snippets" » "sinh vien code snippets", "anh viet code snippets", "ninh viet co snippets", "ninh viet some snippets", "ninh viet 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: (((("ninh viet 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: (((("ninh viet code snippets") OR ("dung cfd code snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( ninh viet code snippets ) or ( dung cfd code snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("ninh viet code snippets") or ("dung cfd code snippets"))) or ("locating bug code snippets"))*.