https://www.amazon.com/Let-Children-Play-Schools-Thrive/dp/0190930969

A new book by William Doyle and Pasi Sahlberg, argues for the quintessential value of self-determined play in the experience of childhood, and includes a chapter on Anji Play, which draws on an interview with founder Ms. Cheng Xueqin, and a survey of the basis of True Play in traditional Chinese philosophy and ethics.