Several influential books on the Trinity were published after his retirement: The Trinitarian Faith: The Evangelical Theology of the Ancient Catholic Church (1988); Trinitarian Perspectives: Toward Doctrinal Agreement (1994); and The Christian Doctrine of God, One Being Three Persons (1996).
Beberapa buku berpengaruh tentang Tritunggal diterbitkan setelah ia pensiun: The Trinitarian Faith: The Evangelical Theology of the Ancient Catholic Church (1988); Trinitarian Perspectives: Toward Doctrinal Agreement (1994); dan The Christian Doctrine of God, One Being Three Persons (1996).