Embleton, T. F.W., J. E. Piercy, and N. Olson. “Sound Propogation Outdoors”. Canadian Acoustics 4, no. 2 (April 1, 1976): 11–19. Accessed May 26, 2024. https://jcaa.caa-aca.ca/index.php/jcaa/article/view/386.