Perhaps you should try some spelling variations:
"dung vien cho snippets" » "duong vien cho snippets", "dung viet cho snippets", "dung tien cho snippets", "dung vien cheo snippets", "dung viec cho snippets", "dung vien cao snippets"
"using a code snippets" » "using a core snippets"
"locating bug code snippets" » "locating bug core snippets", "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 a code snippets") or ("dung vien cho snippets"))) or ("locating bug code snippets"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("using a code snippets") OR ("dung vien cho snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( using a code snippets ) or ( dung vien cho snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("using a code snippets") or ("dung vien cho snippets"))) or ("locating bug code snippets"))*.