SCHLÜRMANN, J. Jan Rüger: Heligoland. Britain, Germany, and the Struggle for the North Sea. Oxford University Press, 2017. Historisk Tidsskrift, [S. l.], v. 118, n. 2, p. 118:2, 559–562., 2019. Disponível em: https://tidsskrift.dk/historisktidsskrift/article/view/115526. Acesso em: 23 sep. 2021.