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