Perhaps you should try some spelling variations:
"dong nhung cong snippets" » "dong nhung code snippets", "dong nhuong cong snippets", "dong hung cong snippets", "dung nhung cong snippets", "dong dung cong snippets", "dong thong cong snippets", "dong hang cong snippets"
"locating bug core snippets" » "locating bug code snippets"
"dung java java snippets" » "dung va java 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 nhung cong snippets") or ("dung java java snippets"))) or ("locating bug core snippets"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("dong nhung cong snippets") OR ("dung java java snippets"))) OR ("locating bug core snippets")).
• Removing quotes may allow a broader search: (((( dong nhung cong snippets ) or ( dung java java snippets ))) or ( locating bug core snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("dong nhung cong snippets") or ("dung java java snippets"))) or ("locating bug core snippets"))*.