Perhaps you should try some spelling variations:
"dong vang cua snippets" » "dong bang cua snippets", "dong van cua snippets", "cong vang cua snippets", "dong mang cua snippets", "dong hang cua snippets", "dong tang cua 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 vang cua 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 vang cua snippets") OR ("dung java java snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( dong vang cua snippets ) or ( dung java java snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("dong vang cua snippets") or ("dung java java snippets"))) or ("locating bug code snippets"))*.