Murphy, D. R., M. Daneman, and B. A. Schneider. “Influence of a Secondary Task on the Understanding of Continuous Discourse by Younger and Older Adults”. Canadian Acoustics, vol. 26, no. 3, Sept. 1998, pp. 94-95, https://jcaa.caa-aca.ca/index.php/jcaa/article/view/1174.