New York: New York Landmarks Conservancy Technical Services Center, ca 2003. First edition. Staplebound Wraps. Octavo, pp. 8, illustrated with b/w photos, laid in is a 2-pg Technical Tips sheet titled "Composite Patching of Brownstone: A Step-by-Step Overview" New. Item #4621
a first-rate study by a group who ought to know the subject!