Birket-Smith, K. (1937). Ragnar Numelin: The Wandering Spirit. A Study of Human Migration. With a Foreword by Dr. Edward Westennarck. H. Hagerup, Copenhagen, Macmillan & Co., London. 1986.875 sider 18 x 26 cm. Pris 20 Kr. Geografisk Tidsskrift, 40. Hentet fra https://tidsskrift.dk/geografisktidsskrift/article/view/48143