Haug, Espen Gaarder. “Measurements of the Planck Length from a Ball Clock Without Knowledge of Newton’s Gravitational Constant G or the Planck Constant”. European Journal of Applied Physics 3, no. 6 (December 2, 2021): 15–20. Accessed September 8, 2024. https://www.ej-physics.org/index.php/ejphysics/article/view/133.