Munro 1902, str. 24–30, Letters of the Sixth Crusade. Munro, Dana Carleton (1902). Letters of the Crusaders. Translations and reprints from the original sources of European history. University of Pennsylvania.
Van Cleve 1969, str. 440–441, Agreement of San Germano. Van Cleve, Thomas C. (1969). The Crusade of Frederick II(PDF). A History of the Crusades (Setton), Volume II.
Van Cleve 1969, str. 443–444, Frederick as King of Jerusalem. Van Cleve, Thomas C. (1969). The Crusade of Frederick II(PDF). A History of the Crusades (Setton), Volume II.
Cazel 1969, str. 129–130, Financing the Crusades. Cazel, Fred A. Jr. (1969). Financing the Crusades(PDF). A History of the Crusades (Setton), Volume VI.
Van Cleve 1969, str. 446–447, The excommunication of Frederick II. Van Cleve, Thomas C. (1969). The Crusade of Frederick II(PDF). A History of the Crusades (Setton), Volume II.
Van Cleve 1969, str. 447, Footnote 64; cf. Huillard-Bréholles, Vol. III. Van Cleve, Thomas C. (1969). The Crusade of Frederick II(PDF). A History of the Crusades (Setton), Volume II.
Van Cleve 1969, str. 451–452, Frederick arrives in Syria. Van Cleve, Thomas C. (1969). The Crusade of Frederick II(PDF). A History of the Crusades (Setton), Volume II.
Van Cleve 1969, str. 453–454, Negotiations with the Sultan. Van Cleve, Thomas C. (1969). The Crusade of Frederick II(PDF). A History of the Crusades (Setton), Volume II.
Van Cleve 1969, str. 455, Muslim reaction to the treaty. Van Cleve, Thomas C. (1969). The Crusade of Frederick II(PDF). A History of the Crusades (Setton), Volume II.