Explore Chicago Collections
https://explore.chicagocollections.org/records/?f7-types=Archival%20Collections&f3-topics=Work%3A%3AAdvertising&browse-topics=yes&f6-types=Archival%20Collections&f2-cities=Elgin&f1-types=Archival%20Collections&f5-institutions=University%20of%20Chicago&f4-topics=Work::Advertising