Perhaps you should try some spelling variations:
"luan danh java snippets" » "luan thanh java snippets", "luan van java snippets", "luan nang java snippets", "luan danh va snippets"
"dung cac co snippets" » "luong cac co snippets", "dung cho co snippets", "dung tai co snippets", "dung cac cong 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: (((("luan danh java snippets") or ("dung cac co snippets"))) or ("locating bug code snippets"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("luan danh java snippets") OR ("dung cac co snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( luan danh java snippets ) or ( dung cac co snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("luan danh java snippets") or ("dung cac co snippets"))) or ("locating bug code snippets"))*.