Perhaps you should try some spelling variations:
"phan kinh co snippets" » "than kinh co snippets", "phan dinh co snippets", "phan minh co snippets", "phan kinh do snippets", "phan tinh co snippets", "phan trinh co 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: (((("phan kinh co snippets") or ("dung java java snippets"))) or ("locating bug code snippets"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("phan kinh co snippets") OR ("dung java java snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( phan kinh co snippets ) or ( dung java java snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("phan kinh co snippets") or ("dung java java snippets"))) or ("locating bug code snippets"))*.