Title of article :
Johannes Kepler Gesammelte Werke, vol. 21.1, Manuscripta Astronomica III; De Calendario Gregoriano; Manuscripta Mathematica: Edited by Volker Bialas, Friederike Boockmann, and Eberhard Knobloch. Munich (Verlag C.H. Beck). 2002. ISBN 3-406474-27-6. 699 pp.
