United States. National Park Service. Preservation Assistance Division. (1989). Preservation tech notes. National Park Service, Preservation Assistance Division.
Citação do estilo Chicago (17ª ed.)United States. National Park Service. Preservation Assistance Division. Preservation Tech Notes. Washington, D.C.: National Park Service, Preservation Assistance Division, 1989.
Citação MLA (8ª ed.)United States. National Park Service. Preservation Assistance Division. Preservation Tech Notes. National Park Service, Preservation Assistance Division, 1989.
Nota: a formatação da citação pode não corresponder 100% ao definido pela respectiva norma.