Perhaps you should try some spelling variations:
"van hanh duoc slippery" » "van hanh thuoc slippery", "van nganh duoc slippery", "van doanh duoc slippery", "van thanh duoc slippery", "ban hanh duoc slippery", "van anh duoc slippery", "van hanh duoc slippers"
"python using a snippets" » "python using a slippers"
"locating bug code snippets" » "locating bug code slippers", "locating bung code snippets", "locating bugs code snippets", "locating bug core 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: (((("python using a snippets") OR ("van hanh duoc slippery"))) OR ("locating bug code snippets"))~.
• Removing quotes may allow a broader search: (((( python using a snippets ) or ( van hanh duoc slippery ))) or ( locating bug code snippets ))~.
• Adding a wildcard symbol may retrieve word variants: (((("python using a snippets") or ("van hanh duoc slippery"))) or ("locating bug code snippets"))*.