Perhaps you should try some spelling variations:
"khoan hoi cac snippets" » "khoan nhoi cac snippets", "khoa hoi cac snippets", "khoa hoc cac snippets", "khoan hoc cac snippets", "khoan voi cac snippets", "khoan hoa 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: (((("khoan hoi 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: (((("khoan hoi cac snippets") OR ("dung java java snippets"))) OR ("locating bug code snippets")).
• Removing quotes may allow a broader search: (((( khoan hoi cac snippets ) or ( dung java java snippets ))) or ( locating bug code snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("khoan hoi cac snippets") or ("dung java java snippets"))) or ("locating bug code snippets"))*.