Ozment, Steven E. The Age of Reform: 1250-1550 : An Intellectual and Religious History of Late Medieval and Reformation Europe. New Haven, Conn. ; London: Yale University Press, 1980. Kindle Electronic Edition.
Chapter 11, “Calvin and Calvinism” pp. 352-381. Part 3, “Strasbourg and Martin Bucer” pp. 362-365.
After his exile from Geneva, Calvin settled in Strasbourg. Under the tutelage of Martin Bucer he learned the art of gradual reform. Bucer was at the center of discussions seeking to reconcile the Lutherans and Zwinglians as well as discussions to reconcile Protestant and Catholic. Calvin was opposed to what he saw as Bucer and Melanchthon neglecting purity of doctrine but he admired their ability as moderators. Calvin continued discourse with the authorities in Geneva while in Strasbourg. He married there in 1540.