APA
(01011988113105). Keeping it clean: removing exterior dirt, paint, stains and graffiti from historic masonry buildings. : National Park Service, Preservation Assistance Division.
Chicago
01011988113105. Keeping it clean: removing exterior dirt, paint, stains and graffiti from historic masonry buildings. : National Park Service, Preservation Assistance Division.
Harvard
(01011988113105). Keeping it clean: removing exterior dirt, paint, stains and graffiti from historic masonry buildings. : National Park Service, Preservation Assistance Division.
MLA
Keeping it clean: removing exterior dirt, paint, stains and graffiti from historic masonry buildings. : National Park Service, Preservation Assistance Division. 01011988113105.