Perhaps you should try some spelling variations:
"cong thuc hanh snippets" » "cong tac hanh snippets", "cong thuc thanh snippets", "cong thuc anh snippets", "cong thuc hinh snippets", "cong thuc hanh slippers"
"dung java java snippets" » "dung va java snippets", "dung java java slippers"
"locating bug code snippets" » "locating bug code slippers", "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 thuc hanh 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 thuc hanh snippets") OR ("dung java java snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( cong thuc hanh snippets ) or ( dung java java snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("cong thuc hanh snippets") or ("dung java java snippets"))) or ("locating bug code snippets"))*.