Letter of Agatho and of the Roman Synod of 125 Bishops
- Translated and edited by Henry R. Percival. Sets out the faith of the Apostolic See, in preparation for the Third Council of Constantinople. From the Nicene and Post-Nicene Fathers of the Christian Church, second series, vol. 14.
- http://www.ccel.org/ccel/schaff/npnf214.xiii.vi.html

Letter to the Emperor
- Translated and edited by Henry R. Percival. With notes. From the Nicene and Post-Nicene Fathers of the Christian Church, second series, vol. 14.
- http://www.ccel.org/ccel/schaff/npnf214.xiii.v.html