Nahm, Michael. “Out of Thin Air? Apport Studies Performed Between 1928 and 1938 by Elemér Chengery Pap”. Journal of Scientific Exploration 33, no. 4 (December 16, 2019). Accessed May 8, 2024. https://www.journalofscientificexploration.org/index.php/jse/article/view/1575.