Perhaps you should try some spelling variations:
"tran hanh cat snippets" » "tran thanh cat snippets", "tran manh cat snippets", "tran anh cat snippets", "tran hanh cac snippets", "tran hanh luat snippets", "tran nhanh cay 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 hanh cat 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 hanh cat snippets") OR ("dung java java snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( tran hanh cat snippets ) or ( dung java java snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("tran hanh cat snippets") or ("dung java java snippets"))) or ("locating bug code snippets"))*.