Perhaps you should try some spelling variations:
"tran tuan cao snippets" » "tran xuan cao snippets", "tran quang cao snippets", "tran thanh cao snippets", "tran toan cao snippets", "tran juan cao 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: (((("tran tuan cao snippets") or ("dung java java snippets"))) or ("locating bug code snippets"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("tran tuan cao snippets") OR ("dung java java snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( tran tuan cao snippets ) or ( dung java java snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("tran tuan cao snippets") or ("dung java java snippets"))) or ("locating bug code snippets"))*.