SCHLÜRMANN, Jan. 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. DOI: 10.7146/ht.v118i2.115526. Disponível em: https://tidsskrift.dk/historisktidsskrift/article/view/115526. Acesso em: 20 feb. 2026.