Perhaps you should try some spelling variations:
"dung trung co snippets" » "dung trong co snippets", "quang trung co snippets", "truong trung co snippets", "dung trung bo snippets", "dung truong cao snippets"
"toc trinh java snippets" » "doc trinh java snippets", "hoc trinh java snippets", "tra trinh 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: (((("toc trinh java snippets") or ("dung trung co snippets"))) or ("locating bug code snippets"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("toc trinh java snippets") OR ("dung trung co snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( toc trinh java snippets ) or ( dung trung co snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("toc trinh java snippets") or ("dung trung co snippets"))) or ("locating bug code snippets"))*.