Perhaps you should try some spelling variations:
"hoc phan long snippets" » "hoc phan luong snippets", "hoc phan cong snippets", "hoc phan song snippets", "hoc dan long snippets", "hoc pho long 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: (((("hoc phan long snippets") or ("dung java java snippets"))) or ("locating bug code snippets"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("hoc phan long snippets") OR ("dung java java snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( hoc phan long snippets ) or ( dung java java snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("hoc phan long snippets") or ("dung java java snippets"))) or ("locating bug code snippets"))*.