Retter, Hein. “The Centenary of William H. Kilpatrick’s “Project Method“: A Landmark in Progressive Education Against the Background of American-German Relations After World War I”. International Dialogues on Education Journal 5, no. 2 (November 27, 2018). Accessed November 21, 2024. https://idejournal.org/index.php/ide/article/view/69.