Impey, Chris D., Matthew C. Wenger, and Carmen L. Austin. “Astronomy for Astronomical Numbers: A Worldwide Massive Open Online Class”. The International Review of Research in Open and Distributed Learning 16, no. 1 (February 11, 2015). Accessed April 25, 2024. https://www.irrodl.org/index.php/irrodl/article/view/1983.