Sylvia Boorstein, Ph.D. (2007). “Pay Attention, for Goodness' Sake: Practicing the Perfections of the Heart--The Buddhist Path of Kindness”, p.20, Ballantine Books
"US Open 2014 – Roger Federer: 'The difference between 142mph and 147mph, there's none really. Once you pass the 135 everything is just really fast'". www.ubitennis.net. August 30, 2014.
"Maria Sharapova Presser: Winning The French, It’s The Most Unique Moment I’ve Experienced In My Career" by Tom Gainey, www.tennis-x.com. June 9, 2012.