Minton, Gretchen E.. John Bale's 'The Image of Both Churches' (angol nyelven). Springer Science & Business Media (2014. január 26.). ISBN 978-94-007-7296-0 „Berengar of Tours was an 11th-century theologian who argued that the doctrine of transubstantiation was contrary to reason and unsupported by scripture”
The Grail Legend (angol nyelven). Princeton University Press (1998. szeptember 1.). ISBN 978-0-691-00237-8 „Berengar of Tours (first half og the eleventh century), whose views occasioned the dispute known as the Second Eucharistic Controversy. Berengar aught that the body and the blood of the Lord were no "real" in the Eucharist but a specific image or likeleness ("figuram quandam similitudinem"). He was thus a forerunner of the Reformers.”
(2016. szeptember 1.) „The forms of communication employed by the Protestant Reformers and especially Luther and Calvin”. Pharos Journal of Theology98. „John of Wessel was one member in the group who attacked indulgences (Reddy 2004:115). The doctrine of justification by faith alone was the teaching of John of Wessel (Kuiper 1982:151). He rejected the doctrine of transubstantiation where it is believed when the priest pronounces the sacraments then the wine and bread in turned into the real body and blood of Christ”