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