Casti, J. (2007). Gregory Chaitin: Mathematician, Philosopher, and Friend. In: Randomness and Complexity, From Leibniz to Chaitin. Eds. Calude, C.S., pp. 417-420 World Scientific Publishing Co.. ISBN 978-981277083-7;9812770828;978-981277082-0 10.1142/9789812770837_0025.