Bernhard Riemann, 1826-1866: Turning Points in the Conception of Mathematics By Detlef Laugwitz. Tr. Abe Shenitzer with the editorial assistance of the author, Hardy Grant, and Sarah Shenitzer. Boston (Birkha¿user). 1999. xvii + 357 pp. ISBN 0-8176-4040-1, 3-7643-4040-1