Perhaps you should try some spelling variations:
"dung phong hoc snippets" » "dung phuong hoc snippets", "duong phong hoc snippets", "rung phong hoc snippets", "dung phong ho snippets", "dung phuong hoa snippets", "dung phong khoa snippets"
"dung using java snippets" » "dung ung java snippets", "dung sinh java snippets", "dung uong java snippets", "dung using data snippets"
"locating bug code snippets" » "locating bung code snippets", "locating bugs code snippets", "locating bug core snippets"

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: (((("dung phong hoc snippets") or ("dung using java snippets"))) or ("locating bug code snippets"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("dung phong hoc snippets") OR ("dung using java snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( dung phong hoc snippets ) or ( dung using java snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("dung phong hoc snippets") or ("dung using java snippets"))) or ("locating bug code snippets"))*.