Olufsen, O. (1920) “Ecuador. Its ancient and modem History, Topography and natural Resources, Industries and social Development, by C. Reginald Enock. With 37 Illustrations and 2 Maps. T. Fisher, Unvin London”., Geografisk Tidsskrift, 25. Tilgængelig hos: https://tidsskrift.dk/geografisktidsskrift/article/view/47095 (Set: 5 december 2025).