Congar, Yves. (1964) The Church: The People of God in Concilium, vol. I. New Jersey: Paulist Press, pp. 11 -- 37.
D'Costa, Gavin. (1986) Theology and Religious Pluralism: The Challenge of Other Religions. Oxford: Blackwell.
Rahner, Karl, S.J. (1968) The Theology of Pastoral Action. New York: Herder.
Karl Barth could be understood as an exclusivist on the basis of the way he opposes "religion" to Christianity in his early work. I would say that by his Church Dogmatics period he had more of an inclusivist position, though one that had little bearing upon his ecclesiology. See Church Dogmatics, trans G.W. Bromiley, II/2 (Edinburgh: T&T Clark, 1957), pp. 417f.