Foote, J., D. Mennill, and L. Ratcliffe. “Utility of Acoustic Location Technology for Studying Avian Dawn Choruses: Social Dynamics of Male Black-Capped Chickadees”. Canadian Acoustics, vol. 34, no. 3, Sept. 2006, pp. 72-73, https://jcaa.caa-aca.ca/index.php/jcaa/article/view/1827.