Perhaps you should try some spelling variations:
"duc phong cac snippets" » "du phong cac snippets", "duc phung cac snippets", "duc hong cac snippets", "duc phong cach snippets", "duc thong cac snippets", "duc phong cai 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: (((("duc phong cac snippets") or ("dung java java snippets"))) or ("locating bug code snippets"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("duc phong cac snippets") OR ("dung java java snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( duc phong cac snippets ) or ( dung java java snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("duc phong cac snippets") or ("dung java java snippets"))) or ("locating bug code snippets"))*.