The Doctrine of the Call in the Confessions and Lutheran Orthodoxy
Dr. Robert David Preus
Influence of the Formula of Concord on Later Lutheran Orthodoxy
Discord, Dialogue, and Concord, Studies in The Lutheran Reformation’s Formula of Concord, 1977, Dr. Rev. Robert D. Preus
Word of God in the Theology of Lutheran Orthodoxy
Concordia Theological Monthly, August 1962 Dr. Rev. Robert D. Preus