Here is a compilation of links and images that reference the bears as Berenstein. Please visit the contact page if you find any other sources of media referencing the bears as Berenstein Bears and wish to add it to the collection.
If anyone has access to online archives via their local library, college or university and willing to share the archive login information it'd be greatly appreciated. As an Australian it's hard to access many overseas archives. New articles and images will be added daily.
Links:
Canadian library catalogue (AMICUS)
Coaster Buzz forum
Literacy Hour and Language Knowledge: Developing Literacy Through Fiction
Practitioner Teacher Inquiry and Research
Archived Australian library
Another Archived Australian library
A list of 22 archived sites referencing Berenstein bear
PennState online library - 2940 results (The authors home town)
4 books entered into openlibrary.org titled with Berenstein
Family Matters - Time article
Government issued teachers handbook
The New York Times - Book Fair Barkers
Australian Ticketmaster - official ticket sales
(Note: use ctrl+F to find the use of Berenstein easier)