"National Register Digital Assets". npgallery.nps.gov. United States Department of the Interior. [1981年]. (原始内容存档于2022-06-17).请检查|access-date=中的日期值 (帮助)
"National Register Digital Assets". npgallery.nps.gov. United States Department of the Interior. [1981年]. (原始内容存档于2022-06-17).请检查|access-date=中的日期值 (帮助)