Perhaps you should try some spelling variations:
"mang viet chi snippets" » "nang viet chi snippets", "anh viet chi snippets", "mai viet chi snippets", "mang viet cho snippets", "mang viec chi snippets", "mang viet chu snippets"
"dung java java snippets" » "dung va java snippets"
"locating bug code snippets" » "locating bung code snippets", "locating bugs code snippets", "locating bug core 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: (((("mang viet chi snippets") or ("dung java java snippets"))) or ("locating bug code snippets"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("mang viet chi snippets") OR ("dung java java snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( mang viet chi snippets ) or ( dung java java snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("mang viet chi snippets") or ("dung java java snippets"))) or ("locating bug code snippets"))*.