Sleptzoff, L. M.. Men or supermen?: The Italian portrait in the fifteenth century. Magnes Press, 1978, p. 68. OCLC4331192. «Cf. E. Steinmann, Ghirlandaio, Leipzig, 1897, pp. 18-21, who recognizes, among the members of the Florentine colony in Rome, Argyropoulos and Giovanni Tornabuoni»