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