1. Authority for the Environment, Climate, Energy, and Agriculture (2022, February). Hamburgs Grün für Kinder und Familien. https://www.hamburg.de/spielplaetze/3932152/faltblatt-spielplaetze/.
2. Averre, D. (2021, October 25). What’s the odd broken bone? The deliberately dangerous German playgrounds designed to teach kids how to handle risk that put our safety-first playpens to shame. Daily Mail. https://www.dailymail.co.uk/news/article-10127735/German-playgrounds-designed-perilous-ensure-kids-learn-handle-risk.html.
3. Banko, Ç., Akdemir, K., Koşar, M. G., & Çelik, S. S. (2018). The investigation of outdoor playgrounds in terms of supporting risky play. Inonu University Journal of the Faculty of Education, 19(3), 406–417. https://doi.org/10.17679/inuefd.387479.
4. Beatson, J. (2019). Play in natural outdoor spaces as a context for learning and language development. He Kupu, 6(2), 69–82.
5. Bilton, H. (2010). Outdoor learning in the early years management and innovation. Routledge.