MARTHA COOPER has been a professional photographer for over 50 years. In addition to Subway Art, she has published numerous other photo books. Her work has been exhibited in museums and galleries worldwide. n nROGER GASTMAN is a collector, as well as the curator and founder of BEYOND THE STREETS, an organization that creates large-scale exhibitions of street art. He is also an accomplished filmmaker and has authored well over 60 books on the subjects of graffiti and street art. n nn