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