ARNE HANSEN, Erik. James Penick, Jr. : Progressive Politics and Conservation. The Ballinger-Pinchot Affair. Chicago and London, The University of Chicago Press, 1968. xvi, 207 s. 79 sh. Historisk Tidsskrift, [S. l.], v. 12, 1973. Disponível em: https://tidsskrift.dk/historisktidsskrift/article/view/51462. Acesso em: 25 dec. 2025.