Perhaps you should try some spelling variations:
proceedings 4th » proceedings 14th, proceedings 6th, proceedings 5th
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 4th) OR (proceedings ec)))) report.
• Adding a wildcard symbol may retrieve word variants: ((proceedings el) or (((proceedings 4th) or (proceedings ec)))) report*.