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 - Danish Journal of Geography, 40. Available at: https://tidsskrift.dk/geografisktidsskrift/article/view/48143 (Accessed: 6 December 2025).