Schicketanz, Juliane, Linus Grabenhenrich, and Tobia Lakes. 2018. “An Index for Assessing Activity Friendliness for Children in Urban Environments of Berlin”. DIE ERDE – Journal of the Geographical Society of Berlin 149 (1):1-13. https://www.die-erde.org/index.php/die-erde/article/view/357.