All Other Sesame Street Books
Many of the Sesame Street books don't focus on one main character, instead the whole cast interacts as an ensemble. All of these books feature the Sesame Street Muppets, but some also feature the human cast as well.
I had a lot of help with the research for this book from the New York City fire department as well as from the local fire department in Putnam, CT, where I lived at the time. The unmasked firefighter who greets Ernie, Grover, and Big Bird is my brother-in-law, Ron.