Perhaps you should try some spelling variations:
"co viet code snippets" » "co viet co snippets", "co viet some snippets", "so viet code snippets", "o viet code snippets", "hoc viet code snippets"
"python using raw snippets" » "python using real snippets", "python using a snippets", "python using low snippets"
"locating bug core snippets" » "locating bug code snippets"

You may be able to get more results by adjusting your search query.

• If you are trying to use Boolean operators, they must be ALL CAPS: (((("co viet code snippets") OR ("python using raw snippets"))) OR ("locating bug core snippets"))~.
• Removing quotes may allow a broader search: (((( co viet code snippets ) or ( python using raw snippets ))) or ( locating bug core snippets ))~.
• Adding a wildcard symbol may retrieve word variants: (((("co viet code snippets") or ("python using raw snippets"))) or ("locating bug core snippets"))*.