Άποψη των τειχών της Τραπεζούντας. Bryer, A., Winfield, R., The Byzantine Monuments and Topography of the Pontos, 2, plates, Dumbarton Oaks Studies 20; Dumbarton Oaks Research Library and Collection, Trustees for Harvard University, Washington D.C., σ. 143. ©Ministry of Culture Directorate General of Monuments and Museums, Ankara