links:
- Didache
- First Epistle of Clement to the Corinthians
- Lumen Gentium
- Tertullian, On Baptism
- Epistle of Barnabas
- Justin Martyr, First Apology
- Irenaeus, Against Heresies, Book III
- Irenaeus, Against Heresies, Book V
- Origen, Origen de Principiis
- Cyprian, Treatise 1
- Cyprian, Treatise 12
- Cyprian, Letter 13
- Cyprian, Letter 26
- Cyprian, Letter 51
- Cyprian, Letter 54
- Cyprian, Letter 62
- Cyprian, Letter 65
- 7th Council of Carthage, Cyprian
- Letter by Cornelius to Cyprian
- Pope John XXII, Quia quorundam
- Vatican I
- Ratzinger, Catholic Theology
- Council, Lateran 4
- Ratzinger, On Professio Fidei