Perhaps you should try some spelling variations:
"cong hoan can snippets" » "cong hoa can snippets", "dong hoa can snippets", "cong san can snippets", "cong toan can snippets", "cong hoang van snippets", "cong hoang 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: (((("cong hoan 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 hoan can snippets") OR ("dung java java snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( cong hoan can snippets ) or ( dung java java snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("cong hoan can snippets") or ("dung java java snippets"))) or ("locating bug code snippets"))*.