Perhaps you should try some spelling variations:
"cong sach dat snippets" » "ong sach dat snippets", "song sach dat snippets", "duong sach dat snippets", "cong sach dao snippets", "cong sach danh snippets", "cong sach bai snippets", "cong sach dat 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 sach dat 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 sach dat snippets") OR ("dung java java snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( cong sach dat snippets ) or ( dung java java snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("cong sach dat snippets") or ("dung java java snippets"))) or ("locating bug code snippets"))*.