RAMSAY, W.; HACKMAN, V. Das Nephelinsyenitgebiet auf der Halbinsel Kola. Fennia - International Journal of Geography, [S. l.], v. 11, n. 1, p. 1–225, 1894. Disponível em: https://fennia.journal.fi/article/view/157174. Acesso em: 24 feb. 2025.