Perhaps you should try some spelling variations:
"cong tich can snippets" » "cong tinh can snippets", "cong lich can snippets", "cong trinh can snippets", "cong tich cac snippets", "cong tich van snippets", "cong dich can 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: (((("cong tich can snippets") or ("dung java java snippets"))) or ("locating bug code snippets"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("cong tich can snippets") OR ("dung java java snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( cong tich can snippets ) or ( dung java java snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("cong tich can snippets") or ("dung java java snippets"))) or ("locating bug code snippets"))*.