Perhaps you should try some spelling variations:
proceedings 2nd » proceedings 2000, proceedings 2001, proceedings 2003
proceedings el » proceedings ed, proceedings etc, proceedings 2
proceedings ec » proceedings etc, proceedings 2, proceedings 1

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

• If you are trying to use Boolean operators, they must be ALL CAPS: ((proceedings el) OR (((proceedings ec) OR (proceedings 2nd)))) report.
• Adding a wildcard symbol may retrieve word variants: ((proceedings el) or (((proceedings ec) or (proceedings 2nd)))) report*.