Invisible Frontier: Exploring the Tunnels, Ruins, and Rooftops of Hidden New York [Book]

Available from Amazon (Paperback)

Deyo, LB & Leibowitz, David.
Invisible Frontier: Exploring the Tunnels, Ruins, and Rooftops of Hidden New York.
Three Rivers Press, New York, 2003
ISBN-13: 978-0609809310