Perhaps you should try some spelling variations:
"cong trinh trac snippets" » "cong trinh trang snippets", "cong trinh toan snippets", "cong trinh tai snippets", "cong trinh trac slippers"
"dung ung code snippets" » "dung trung code snippets", "dung quang code snippets", "dung chung code snippets", "dung ung co snippets", "dung ung code slippers"
"locating bug code snippets" » "locating bug code slippers", "locating bung code snippets", "locating bugs code 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 trinh trac snippets") or ("dung ung code snippets"))) or ("locating bug code snippets"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("cong trinh trac snippets") OR ("dung ung code snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( cong trinh trac snippets ) or ( dung ung code snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("cong trinh trac snippets") or ("dung ung code snippets"))) or ("locating bug code snippets"))*.