Sacraments in the Medieval Church

	Beresford James Kidd [1864-1948], The Later Medieval Doctrine of the Eucharistic Sacrifice. London: SPCK, 1958. Pbk. pp.104. pdf [This material is in the Public Domain]
	A.J. MacDonald, Berengar and the Reform of Sacramental Doctrine. London: Longmans, Green & Co. Ltd., 1930. pp.xii+444.
	David S. Schaff, "The Sacramental Theory of the Mediæval Church," The Princeton Theological Review 4.2 (1906): 206-235. pdf [This material is in the Public Domain and can be freely distributed and copied]
	J.W.C. Wand, The Development of Sacramentalism. London: Methuen & Co., 1928. pp.173.