Perhaps you should try some spelling variations:
"dong cong cao snippets" » "duong cong cao snippets", "dung cong cao snippets", "dang cong cao snippets", "dong cong cau snippets", "dong cong cac snippets", "dong cong co 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: (((("dong cong 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: (((("dong cong cao snippets") OR ("dung java java snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( dong cong cao snippets ) or ( dung java java snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("dong cong cao snippets") or ("dung java java snippets"))) or ("locating bug code snippets"))*.