Major focuses for these theologians during the period are in chronological order: Christianity's relationship with Judaism; the establishment of the New Testament Canon; Apologetics ('defense' or 'explanation' of Christianity); and doctrinal discussions that sought to achieve consistency of faith, in particular within the Christianized Roman Empire. Following the scholar of Christianity Alistair McGrath (1998), several major areas of theology can be seen to have developed during the Patristic Period: the extent of the New Testament Canon, the role of tradition, the fixing of the ecumenical creeds, the Two Natures of Christ, the doctrine of the Trinity, the doctrine of the Church, and the doctrine of Divine grace. [from Alistair McGrath’s Historical Theology: An Introduction to the History of Christian Thought. Chapter 1: “The Patristic Period."]
A history of Christian thought / Justo L. Gonzalez.
Catholicity and heresy in the early church / Mark Edwards.
Christology of the later Fathers, edited by Edward Rochie Hardy
Early Christian creeds / J.N.D. Kelly.
Early Christian doctrines / by J.N.D. Kelly.
Early Modern Catholicism: An Anthology of Primary Sources
History of theology Set (see vol. I)
Learning theology with the church fathers / Christopher A. Hall.
Manual of Patrology and History of Theology.
Message of the Fathers of the Church Series
On the Incarnation / St. Athanasius the Great of Alexandria ; preface by C.S. Lewis ; translation and introduction by John Behr by 
Sources of Early Christian Thought Series
The teachings of the Church Fathers / edited by John R. Willis.
Decrees of the ecumenical councils / edited by Norman P. Tanner. Selected resources include:
The councils of the church : a short history / Norman P. Tanner.
