Perhaps you should try some spelling variations:
"luan toan cong snippets" » "luan hoan cong snippets", "xuan toan cong snippets", "luan thanh cong snippets", "luan tran cong snippets", "luan toan thong snippets", "luan doan cuong 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: (((("luan toan cong snippets") or ("dung java java snippets"))) or ("locating bug code snippets"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("luan toan cong snippets") OR ("dung java java snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( luan toan cong snippets ) or ( dung java java snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("luan toan cong snippets") or ("dung java java snippets"))) or ("locating bug code snippets"))*.