Faulring, Andrew, Ken Mohnkern, Aaron Steinfeld, and Brad Myers. “The Design and Evaluation of User Interfaces for the RADAR Learning Personal Assistant”. AI Magazine 30, no. 4 (September 18, 2009): 74. Accessed September 21, 2020. https://www.aaai.org/ojs/index.php/aimagazine/article/view/2265.