Perhaps you should try some spelling variations:
"dung viet ngu snippets" » "nang viet ngu snippets", "cong viet ngu snippets", "mang viet ngu snippets", "dung viet nam snippets", "dung viet tu snippets", "dung viet ngu slippers"
"using c code snippets" » "using lc code snippets", "using a code snippets", "using _ code snippets", "using cfd code snippets", "using c 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: (((("using c code snippets") or ("dung viet ngu snippets"))) or ("locating bug code snippets"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("using c code snippets") OR ("dung viet ngu snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( using c code snippets ) or ( dung viet ngu snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("using c code snippets") or ("dung viet ngu snippets"))) or ("locating bug code snippets"))*.