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.